Sounds odd.
Can you share your inputs (.xmls)? Are you using depletion? (can be heavy on RAM)
I could run it and see how much RAM it requires on my system, or what else could be going awry.
Compiling the code always has a number of nuances on different systems.
Seems compiling on Apple M1 and arm64 can be tricky:
(OpenMC installtion Mac Apple M1 chip)
Perry