Reproduction steps:
1. Open customer's project attached in "BugUIToolkit (iOS hover).zip" (379.7 KB)
2. Open EntryPoint Scene
3. Build for iOS and deploy the project to a device
4. Tap and release on any of the red buttons

Expected result: The button turns blue during the press and goes back to being red after releasing it
Actual result: The button stays yellow until the screen is tapped somewhere else (not the button that is yellow currently) (Read notes below)

Reproducible with: UI Toolkit 1.0.0-preview.14 (2020.3.4f1)
Not reproducible with: UI Toolkit 1.0.0-preview.14 (2021.1.4f1)
Could not test with: 2019.4.24f1, 2021.2.0a13 because of namespace and package errors that I could not resolve

Notes:
1. Yellow color indicated hover state, this should not happen in this scenario
2. In 2021.1.4f1, the button does not remain yellow, bet when pressing another button, both become blue, indicating the press
3. This is caused by enabling "Both" for "Active Input Handling" but letting UI Toolkit use Input Manager (old) by not adding an Event System on the scene
4. Another issue is that when pressing one button and then another button both the current and previous buttons indicate a press