@leocg It happens on any video player, be it Zoom Recordings, YouTube itself or videos imbedded in another page, even the external player.
I've seen it happen for every video I've played in the last month.
I tested disabling the Extensions, I only had Opera AdBlock and uBlock, but the issue still reproduced.
Any suggestions?

@leocg
I've just reinstalled Opera GX and reinstalled the latest installer, and the issue is still there, even in multiple profiles.
This doesn't happen on my laptop, just my desktop PC.
I also found that scrolling up or down will remove the border for a second:

Is there anything I could do aside from Uninstalling the browser to delete any remaining data left? deleting some logs, running a cleaning tool, etc?

Adding screenshots to show the border, I've just tested it on Netflix and it happens there as well.

Hey Everyone!
I'm having an issue with black borders appearing in every video that plays in Opera GX, this is mostly an issue because the border crops the video, it's not just around it.
I've found a couple posts here reporting the same but the solution of disabling 'Force Dark Theme' didn't work, and I tested disabling all extentions, ad-blockers, reseting settings and flags, and this happens in two different profiles, so it's not specific to a profile.
I'm using Windows 10, the GX version is: LVL4 (core: 98.0.4759.64)
The issue happens for all video players in the browser, Youtube, Zoom Recordings, etc, I've even noticed it on the pop-out video window that Opera has.

Any ideas on how to get rid of it?
Thank you very much!