Hey there.
I don’t know if this is a known problem.
I was having problems loading bigger NeoGeo roms such as Sengoku 3 and KoF 96: they kept crashing Retro Arch.
I’ve tried everything to solve it (deleting cfg files, restoring the core, etc.) without success. Then I remembered that I’ve turned “rewind” on a few days ago. Bingo. Turned it off and the problem was solved.