Fx Plc memory bit failure

I have an Mitsubishi fx-2n-48-mrds. I noticed that some of the memory bits seem to act funny. Some of the latched ones do not stay latched and random ones turn on by themself after a power cycle. Can memory bits go bad after time?

Thanks,
Steve

It will almost certainly be a software error where a memory location is being written to from more than one place.
Often it is 32 bit numbers that overlap.