I've shot a photo stack of tens of photos today using a steady tripod. However, in my results, some of my photos are randomly rotated incorrectly. It's both in camera and in Bridge and anywhere else. Here is a screenshot from Bridge:
The Camera/Tripod did not move even a tiny bit between these shots. I always take astrophotography stacks with the same equipment but this is the first time I've ever encountered such issue. I think I will rotate them manually selectively, but I want to understand why I'm facing this issue in the first place.