Macbook brightens video while dimming rest of display

Macbook Pro

Apple M1 Max

Monterey 12.4

Hard to explain this.

Sometimes I play a video on instagram (and fb) and the video becomes very bright, washed out highlights, while the rest of the screen begins to dim. Did I hit a shortcut key to "highlight" a video? The screen does not go back to normal when I close the video and restart the computer. It stays dim. If I reopen ig with a video, the video is bright though. Weird! What do I do to get my screen back to normal. It's been days since my screen has been dim. I took a picture with my camera because I don't know how else to describe it.

I use Firefox as my browser, and I have an external display. This has been my setup for years, no issues before. I think it's some kind of shortcut key or software focus issue. I have unplugged my external monitor and closed Firefox, restarted the computer, opened the same video in Safari and everything including the video is dim. I re-open Firefox on the same video and the video is bright! Everything else is dim.

Anyway, I would appreciate help to get my computer back to normal if anyone knows anything. I will head out to the apple store this week otherwise. Thanks!