In UE4 I always installed the engine code on my second drive, E:. It worked great, never had any problems.
With UE5 the way the ROOTDIR and SDK pathing is setup installing the source code on my second drive proved to be an absolute nightmare. It was one problem after the other. SDK’s not loading, scripts not loading, automation tool not working.
All my problems went away as soon as I moved everything to C:
Recommend you do the same for now to save yourself a huge amount of hassle and wasted time trying to deal with pathing issues.