Updated to 83.0.4254.54 (not 83.0.4254.62) from stable opera's deb. repo and Minimize button is working (no bug there) and also I don't see this flickering in taskbar that I saw sometimes when multiple Opera had multiple windows opened (hence multiple icons in taskbar).
All tested on latest stable Kubuntu (KDE).

That's awesome, thank you guys!

OK, so failing to minimize can be workaround'ed with "Window rule" in KDE. But another bug is that flickering in taskbar when you click on "buggy" minimize (on Opera window title bar, not native window title bar I've added with specific rule in KDE). This flickering causes slowdown of UI in system and the only solution I see when it starts flickering - restore from maximized state (either "Restore" window, or minimize with native window witle bar).
Really hope it'll get fixed soon. These 2 bugs has been around for probably 3-4 months it feels like.

Updated to 83.0.4254.54 (not 83.0.4254.62) from stable opera's deb. repo and Minimize button is working (no bug there) and also I don't see this flickering in taskbar that I saw sometimes when multiple Opera had multiple windows opened (hence multiple icons in taskbar).
All tested on latest stable Kubuntu (KDE).

That's awesome, thank you guys!

@burnout426 said in Opera Failing to Minimize:

Yeah, the non-snap version of 83.0.4254.27. has this bug too.

Yep, confirm, have the same buggy version.
BTW, where did you read that it's fixed in 83.0.4254.62 ?

OK, so failing to minimize can be workaround'ed with "Window rule" in KDE. But another bug is that flickering in taskbar when you click on "buggy" minimize (on Opera window title bar, not native window title bar I've added with specific rule in KDE). This flickering causes slowdown of UI in system and the only solution I see when it starts flickering - restore from maximized state (either "Restore" window, or minimize with native window witle bar).
Really hope it'll get fixed soon. These 2 bugs has been around for probably 3-4 months it feels like.