@sgunhouse .I can't drag the edges or the corner. What icon you're talking about?

I'm having a strange problem. When I upload or download something with Opera and the window explorer popup it stayed at maximize size and can't be resize. I drag the explorer window and it do nothing. This happen with both Opera and Opera GX. I tried clean uninstall and reinstall, reset browser. Nothing work.
I search google but it seem I'm the only one have this problem. I would like to continue use Opera but until I can find a fix for this I will have to use Edge or Chrome instead.

Video
https://youtu.be/O7Dnd2ZLJec