Flipped Footage Glitch

[SpicyMcHagges]

This is my 2nd time encountering this problem, but all of my footage is flipped upside down. I can individually edit every clip and picture to rotate it back to normal, but it either is too much effort or somehow magically flips itself back to normal and I have to undo my edits to each clip and picture.

Why is this happening? And how do I fix it?