I took some pictures with Polaroid Originals' 600 B&W film and aside from a general lack of sharpness, several months after the shots, some orange color casting is starting to appear in the top areas of all frames. It's only a narrow blurry band centered right at the top. It doesn't reach the top corners in most cases.
I can't be sure when it all started, I just recently noticed. Pictures were taken last year March to June (the same single 600 cartridge). I also feel that after these months they have been slowly losing sharpness and contrast in the bottom part (albeit that being much less apparent).
The film was stocked in the fridge until the very first shot, but it remained in camera afterwards. This weird color casting wasn't there when I last checked on them at the end of the year and they have been stored in a box inside a closet (with barely any change in humidity and without extreme temperature changes).
Here's a sample: