Chromium 96 (and newer) changes how Shadow DOM works. Changes are required.
The Selenium Core Team has anticipated this, and has added a new way to interact with the shadow root elements via element.shadow_root in Selenium 4.1.0. Currently, SeleniumBase uses the ::shadow selector for piercing through shadow root elements. A change will need to be made to allow that ::shadow selector to continue functioning with Chromium 96 (and newer).