diff --git a/src/Http/Http/perf/Microbenchmarks/AdaptiveCapacityDictionaryBenchmark.cs b/src/Http/Http/perf/Microbenchmarks/AdaptiveCapacityDictionaryBenchmark.cs
index 40684acda48f..fd7a2e06db2a 100644
--- a/src/Http/Http/perf/Microbenchmarks/AdaptiveCapacityDictionaryBenchmark.cs
+++ b/src/Http/Http/perf/Microbenchmarks/AdaptiveCapacityDictionaryBenchmark.cs
@@ -40,7 +40,11 @@ public void Setup()
 
             _smallCapDict = new AdaptiveCapacityDictionary<string, string>(capacity: 1, StringComparer.OrdinalIgnoreCase);
             _smallCapDictTen = new AdaptiveCapacityDictionary<string, string>(capacity: 10, StringComparer.OrdinalIgnoreCase);
-            _filledSmallDictionary = new AdaptiveCapacityDictionary<string, string>(_tenValues, capacity: 10, StringComparer.OrdinalIgnoreCase);
+            _filledSmallDictionary = new AdaptiveCapacityDictionary<string, string>(capacity: 10, StringComparer.OrdinalIgnoreCase);
+            foreach (var a in _tenValues)
+            {
+                _filledSmallDictionary[a.Key] = a.Value;
+            }
 
             _dict = new Dictionary<string, string>(1, StringComparer.OrdinalIgnoreCase);
             _dictTen = new Dictionary<string, string>(10, StringComparer.OrdinalIgnoreCase);
diff --git a/src/Http/Http/src/Internal/RequestCookieCollection.cs b/src/Http/Http/src/Internal/RequestCookieCollection.cs
index e3554d5a711b..b9036c5572da 100644
--- a/src/Http/Http/src/Internal/RequestCookieCollection.cs
+++ b/src/Http/Http/src/Internal/RequestCookieCollection.cs
@@ -70,7 +70,9 @@ internal static RequestCookieCollection ParseInternal(StringValues values, bool
             {
                 return Empty;
             }
-            var collection = new RequestCookieCollection(values.Count);
+
+            // Do not set the collection capacity based on StringValues.Count, the Cookie header is supposed to be a single combined value.
+            var collection = new RequestCookieCollection();
             var store = collection.Store!;
 
             if (CookieHeaderParserShared.TryParseValues(values, store, enableCookieNameEncoding, supportsMultipleValues: true))
diff --git a/src/Http/Http/test/RequestCookiesCollectionTests.cs b/src/Http/Http/test/RequestCookiesCollectionTests.cs
index 8d3dad77f620..1e886bc2f3cf 100644
--- a/src/Http/Http/test/RequestCookiesCollectionTests.cs
+++ b/src/Http/Http/test/RequestCookiesCollectionTests.cs
@@ -38,5 +38,13 @@ public void AppContextSwitchUnEscapesKeysAndValues(string input, string expected
             Assert.Equal(expectedKey, cookies.Keys.Single());
             Assert.Equal(expectedValue, cookies[expectedKey]);
         }
+
+        [Fact]
+        public void ParseManyCookies()
+        {
+            var cookies = RequestCookieCollection.Parse(new StringValues(new[] { "a=a", "b=b", "c=c", "d=d", "e=e", "f=f", "g=g", "h=h", "i=i", "j=j", "k=k", "l=l" }));
+
+            Assert.Equal(12, cookies.Count);
+        }
     }
 }
diff --git a/src/Shared/Dictionary/AdaptiveCapacityDictionary.cs b/src/Shared/Dictionary/AdaptiveCapacityDictionary.cs
index 910e3e9244da..d39f2647a9ff 100644
--- a/src/Shared/Dictionary/AdaptiveCapacityDictionary.cs
+++ b/src/Shared/Dictionary/AdaptiveCapacityDictionary.cs
@@ -77,29 +77,6 @@ public AdaptiveCapacityDictionary(int capacity, IEqualityComparer<TKey> comparer
             else
             {
                 _dictionaryStorage = new Dictionary<TKey, TValue>(capacity);
-                _arrayStorage = Array.Empty<KeyValuePair<TKey, TValue>>();
-            }
-        }
-
-        /// <summary>
-        /// Creates a <see cref="AdaptiveCapacityDictionary{TKey, TValue}"/> initialized with the specified <paramref name="values"/>.
-        /// </summary>
-        /// <param name="values">An object to initialize the dictionary. The value can be of type
-        /// <see cref="IDictionary{TKey, TValue}"/> or <see cref="IReadOnlyDictionary{TKey, TValue}"/>
-        /// or an object with public properties as key-value pairs.
-        /// </param>
-        /// <remarks>This constructor is unoptimized and primarily used for tests.</remarks>
-        /// <param name="comparer">Equality comparison.</param>
-        /// <param name="capacity">Initial capacity.</param>
-        internal AdaptiveCapacityDictionary(IEnumerable<KeyValuePair<TKey, TValue>> values, int capacity, IEqualityComparer<TKey> comparer)
-        {
-            _comparer = comparer ?? EqualityComparer<TKey>.Default;
-
-            _arrayStorage = new KeyValuePair<TKey, TValue>[capacity];
-
-            foreach (var kvp in values)
-            {
-                Add(kvp.Key, kvp.Value);
             }
         }
 
diff --git a/src/Shared/test/Shared.Tests/AdaptiveCapacityDictionaryTests.cs b/src/Shared/test/Shared.Tests/AdaptiveCapacityDictionaryTests.cs
index b31ae8e14928..e8be275fe43d 100644
--- a/src/Shared/test/Shared.Tests/AdaptiveCapacityDictionaryTests.cs
+++ b/src/Shared/test/Shared.Tests/AdaptiveCapacityDictionaryTests.cs
@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using Microsoft.AspNetCore.Internal;
 using Microsoft.AspNetCore.Testing;
@@ -38,66 +39,23 @@ public void CreateFromNull()
             Assert.Null(dict._dictionaryStorage);
         }
 
-        public static KeyValuePair<string, object>[] IEnumerableKeyValuePairData
-        {
-            get
-            {
-                return new[]
-                {
-                    new KeyValuePair<string, object?>("Name", "James"),
-                    new KeyValuePair<string, object?>("Age", 30),
-                    new KeyValuePair<string, object?>("Address", new Address() { City = "Redmond", State = "WA" })
-                };
-            }
-        }
-
-        public static KeyValuePair<string, string>[] IEnumerableStringValuePairData
-        {
-            get
-            {
-                return new[]
-                {
-                    new KeyValuePair<string, string>("First Name", "James"),
-                    new KeyValuePair<string, string>("Last Name", "Henrik"),
-                    new KeyValuePair<string, string>("Middle Name", "Bob")
-                };
-            }
-        }
-
         [Fact]
-        public void CreateFromIEnumerableKeyValuePair_CopiesValues()
+        public void CreateWithCapacityOverDefaultLimit()
         {
-            // Arrange & Act
-            var dict = new AdaptiveCapacityDictionary<string, object?>(IEnumerableKeyValuePairData, capacity: IEnumerableKeyValuePairData.Length, EqualityComparer<string>.Default);
+            // The default threshold between array and dictionary is 10. If we created one over that limit it should go directly to a dictionary.
+            var dict = new AdaptiveCapacityDictionary<string, string>(capacity: 12, StringComparer.OrdinalIgnoreCase);
 
-            // Assert
-            Assert.IsType<KeyValuePair<string, object?>[]>(dict._arrayStorage);
-            Assert.Collection(
-                dict.OrderBy(kvp => kvp.Key),
-                kvp =>
-                {
-                    Assert.Equal("Address", kvp.Key);
-                    var address = Assert.IsType<Address>(kvp.Value);
-                    Assert.Equal("Redmond", address.City);
-                    Assert.Equal("WA", address.State);
-                },
-                kvp => { Assert.Equal("Age", kvp.Key); Assert.Equal(30, kvp.Value); },
-                kvp => { Assert.Equal("Name", kvp.Key); Assert.Equal("James", kvp.Value); });
-        }
+            Assert.Null(dict._arrayStorage);
+            Assert.NotNull(dict._dictionaryStorage);
 
-        [Fact]
-        public void CreateFromIEnumerableStringValuePair_CopiesValues()
-        {
-            // Arrange & Act
-            var dict = new AdaptiveCapacityDictionary<string, string>(IEnumerableStringValuePairData, capacity: 3, StringComparer.OrdinalIgnoreCase);
+            for (var i = 0; i < 12; i++)
+            {
+                dict[i.ToString(CultureInfo.InvariantCulture)] = i.ToString(CultureInfo.InvariantCulture);
+            }
 
-            // Assert
-            Assert.IsType<KeyValuePair<string, string>[]>(dict._arrayStorage);
-            Assert.Collection(
-                dict.OrderBy(kvp => kvp.Key),
-                kvp => { Assert.Equal("First Name", kvp.Key); Assert.Equal("James", kvp.Value); },
-                kvp => { Assert.Equal("Last Name", kvp.Key); Assert.Equal("Henrik", kvp.Value); },
-                kvp => { Assert.Equal("Middle Name", kvp.Key); Assert.Equal("Bob", kvp.Value); });
+            Assert.Null(dict._arrayStorage);
+            Assert.NotNull(dict._dictionaryStorage);
+            Assert.Equal(12, dict.Count);
         }
 
         [Fact]
@@ -114,23 +72,6 @@ public void CreateFromIEnumerableKeyValuePair_ThrowsExceptionForDuplicateKey()
                 $"An element with the key 'Name' already exists in the {nameof(AdaptiveCapacityDictionary<string, object?>)}.");
         }
 
-        [Fact]
-        public void CreateFromIEnumerableStringValuePair_ThrowsExceptionForDuplicateKey()
-        {
-            // Arrange
-            var values = new List<KeyValuePair<string, string>>()
-            {
-                new KeyValuePair<string, string>("name", "Billy"),
-                new KeyValuePair<string, string>("Name", "Joey"),
-            };
-
-            // Act & Assert
-            ExceptionAssert.ThrowsArgument(
-                () => new AdaptiveCapacityDictionary<string, string>(values, capacity: 3, StringComparer.OrdinalIgnoreCase),
-                "key",
-                $"An element with the key 'Name' already exists in the {nameof(AdaptiveCapacityDictionary<string, object>)}.");
-        }
-
         [Fact]
         public void Comparer_IsOrdinalIgnoreCase()
         {