Whenever I apply anything in the FX menu or any affects similar to that, it does that same change to all other frames. This affects all layers apart from locked ones btw. It’s never done this before so I assume it’s some sort of bug, but I could have also changed some random setting without knowing it.
What Color Mode are you using Indexed or RGB Color?
Welcome @Ara, from your video it looks like this issue is related to the “All” option in the “Brightness/Contrast” dialog (you can click it to change it to “Selected”):
oh, wow, I’m an idiot =.= I didn’t even know that was a changeable option, thank you!
Actually the option is a little hidden, not quite straightforward to see what is happening/could happen/what is for this button. Something to improve in the future.