Windows Defender removing files after install (FitGirl repack) – best practice?

Hey all, looking for some technical clarity.

I recently installed a game from a FitGirl repack. During installation, Windows Defender was blocking certain files, so I temporarily disabled Defender, completed the install, and the game ran fine.

After turning Defender back on the next day, it quarantined/deleted some game files, and now the game won’t launch.

A friend told me I shouldn’t disable Defender at all. He installs FitGirl repacks without turning Defender off and runs them without issues, but he mostly plays older single-player titles, not newer games like COD.

Trying to understand:

Why Defender flags files after re-enabling

Whether newer cracks/executables trigger more aggressive heuristics

If restoring from quarantine is safe or if reinstalling is better

What the recommended workflow is on Windows 11

System: Ryzen 7 9700X | RTX 5070 Ti | 32GB RAM | Windows 11

Not looking to compromise system security—just want to handle this the correct way. Appreciate any insight.