They might be having a problem interpeting RAW files and/or settings written in the file by the firmware, but it's not a firmware problem.
Maybe not in the strict sense, but expand your idea of "firmware problem" to include "documentation of RAW files" and "consistency of RAW files between firmware versions".
The manifestation of the problem (eg when you go to another folder) makes it look like strictly a P1 problem, but the trigger event might well be unexpected values in the RAW file with the visible problems being side-effects. Not saying this is the case, just that it's possible. It seems to be dependent upon camera WB settings.
In any case, this is all just idle speculation at this point, of little value other than to deduce work-arounds or ways to avoid the problem until P1 has diagnosed and fixed the problem.