Unreal Engine Lyra documentation
Xist Lyra documentation - You can learn Unreal Engine related things too
DISABLE Anti-virus and Windows Defender from performing real-time scans on source directories.
If you fail to do this, every time you switch branches (which can affect 10000s of files in UE), it will re-scan for viruses. It’s an insane waste of time. Just turn it off.
Corollary: Keep viruses out of your source directories. :P