Acer CB281HK - yellowish tint on screen ONLY when playing video on full screen

InsideJobs

I'm hoping someone can help figure this out for me....

I'm not sure what if any settings I may have changed, but I think I may have gone and done something when trying to change the brightness by mistake. 

This monitor is plugged into a MacBook Pro 2020. If I start to play a video (I've tried YouTube and Vimeo), it will play for a few seconds with the color/tint looking absolutely fine, but within a few seconds, the screen changes and starts to display the video with a slight yellowish hue.

However, this is ONLY when I select 'full screen.'  If I don't enlarge the video to full screen for viewing, it doesn't change and will play without any color change.  It also seems to only be happening with videos. If I watch the same full screen video on built in MacBook Pro display, it doesn't change.  

I'm stumped as to what's going on here. 

Thanks!