Graphics dim upon match start

[john44]

Steps to reproduce:

- Start a match
- In lobby, note correct graphics brightness
- As soon as game countdown starts, note graphics have dimmed

Screenshots attached.

Attempted fixes:
- Borderless window vs Fullscreen
- Changing brightness in fullscreen
- Different graphics card RTX 4060 and RTX 5070
- Clean install of new nvidia drivers
- Disable nvidia overlay, game filters
- Disable Steam overlay
- Different monitors M28U (Displayport) and Dell Ultrafine 5k (Thunderbolt)
- Uninstall game, delete Deadlock folder, re-install game
- I also reinstalled Windows during this time