Yes, it was a problem with LSI, it kept resetting:
Apr 17 13:38:11 NAS-NG kernel: mpt2sas_cm0: fault_state(0x2622)!
Apr 17 13:38:11 NAS-NG kernel: mpt2sas_cm0: sending diag reset !!
Apr 17 13:38:12 NAS-NG kernel: mpt2sas_cm0: diag reset: SUCCESS
But strange that booting UEFI would cause this, I have no issues with that. might not be the reason, unless it's some BIOS bug.