How to reproduce:
1. Open the user's attached project
2. Open scene Scenes/SampleScene
3. In the Hierarchy window, select "EventSystem"
4. Enable the EventSystem by enabling the checkbox next to its name in the Inspector view
5. Go to File -> Build Settings and select Add Open Scenes
6. Build and run the project for Linux
7. In the running build, select the UITK Text Field
8. Attempt to use Backspace to delete characters from the text field

Expected result: backspace deletes characters from the text field
Actual result: backspace does not work to delete characters from the text field

Reproducible with: 2021.3.1f1, 2022.1.0f1, 2022.2.0a11
Could not test with: 2019.4.38f1, 2020.3.34f1 (UI Toolkit elements missing)

Notes:
1. Reproduces in the Editor as well as in builds
2. Sometimes using Delete on the UI Toolkit text field yields special characters and these errors: "The character with Unicode value \\u007F was not found in the \[] font asset or any potential fallbacks. It was replaced by Unicode character \\u25A1."