Mouse input is not blocked when Steam Overlay is open

How to reproduce:
1. Open the attached project "IN-133408"
2. Build the project
3. Add the build to Steam as a Non-Steam game by selecting "Games > Add a Non-Steam Game to My Library..." in the Steam menu bar
4. Open the game using Steam
5. In the game, press 'Shift' + 'Tab' to open the Steam Overlay
6. Observe the in-game buttons while left-clicking on them with the Overlay open

Actual result: The buttons are able to be pressed down while the Steam Overlay is open
Expected result: The buttons cannot be pressed down while the Steam Overlay is open

Reproducible with: 1.10.0 (6000.0.57f1), 1.18.0 (6000.0.57f1, 6000.0.67f1, 6000.3.8f1, 6000.4.0b8, 6000.5.0a6)
Not reproducible with: 1.10.0 (6000.0.56f1), 1.18.0 (6000.0.56f1)

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Notes:

• Keyboard input is blocked
• Also tested with Discord Overlay where the issue did not reproduce