Can't close mobile search bar once typed

[BenGlassAtlas]

Preconditions

1. Magento 2.1.9 using the Luma theme (no customisations)

Steps to reproduce

1. Load the homepage on a mobile device
2. Tap on the search icon to access the search input
3. Start typing (but do not submit)
4. Now tap on the search icon again to close the search bar

Sometimes it will close, but if you open it again it will not close.

Expected result

1. Search bar closes

Actual result

1. Nothing, search bar stays open

Happens on iOS and Android devices using different browsers, it's because the active class is not removed.

I suspect this issue was introduced as a fix for #4282

GIF

Recorded on an iPhone 5s emulator running iOS 10.3 but can replicate it on real iPhone 7 running iOS 11 to (amongst other devices including Android).

[magento-engcom-team]

@BenSpace48, thank you for your report.
We've created internal ticket(s) MAGETWO-81048 to track progress on the issue.