How to reproduce:
1. Open the attached project "InputBugRepro.zip"
2. Open "GameScene" in the Assets / _Scenes folder
3. Enter Play Mode
4. Press the Space bar two times to add the player and start the game
5. Press the Esc key to open the menu
6. Press the middle button in the game called "Resume"
7. Repeat steps 5 and 6

Expected result: "Resume" button responds to a mouse click on the first click
Actual result: "Resume" button responds only after the second click

Reproducible with: 1.1.0-pre.6, 1.1.1 (2019.4.31f1, 2020.3.21f1, 2021.1.26f1, 2021.2.0b16), 1.1.1 (2022.1.0a12)
Not reproducible with: 1.0.0-pre.5 (2019.4.31f1, 2020.3.21f1, 2021.1.26f1, 2021.2.0b16)
Could not test with: 1.1.0-pre.5, 1.1.0-pre.6 (2022.1.0a12) - Packages are not available

Notes:
Buttons "Leave" and "Options" behave the same
Clicking anywhere in the game before pressing any of the buttons makes the button respond to a single click
When pointing the mouse to a button and pressing the Enter key the buttons respond in one press