While I'm not sure about every past instance of the problem on my end, since a few days ago I noticed that more or less every day the problem showed up. I thought "Wth is going on ? What possible change did I introduce in my OS/app usage that may have escalated this ?". Then it hit me that I have been away from home often while PC is on by switching user (not logging off) so that no one can access and mess up my account / current session.

So it seems after "logging in" back to my account / ongoing session, Opera runs into the problem that is the subject of this thread.

Yesterday the problem bug reappeared again (Windows 7 Home Premium 32bit English, Opera 58.0.3135.79). I kept going fo awhile until I had enough and restarted Opera; problem gone again for now.

I'm quite busy to try standalone opera for the moment. Since I would have to run it for days and days (in search for the bug), I would have to import stuff from regular installation and do other tweaks etc. Maybe later. Of course I should participate to pinpoint the problem, and when the time is right I will. For the time being I'll just have to restart Opera when the bug manifests again.

@burnout426

Sorry for being so late to reply. Installing opera as standalone will require I run it frequently along with the normal installation. Why ? because in the normal installation the problem doesn't show up at all times, but seems to happen once every x sessions. So when the problem shows up, it keeps manifesting for that whole session. Sometimes it will not be there next sessions, and sometimes it will. Last time it showed up (upon which I wrote my last comment), I don't remember if I restarted the browser that same day (hence new session) or not, but the next day I didn't notice it. Few days later (few day eariler than now) It showed up again, and I again haven't noticed it after that.

I do not use opera sync at all. Also, when I wrote in my last post that the problem showed up again when I was in deviantart, I didn't mean that it suddenly happend in that site where as it didn't happen earlier. It's just that I didn't go fullscreen before I visited deviantart. Also, it's no specific URL when theat bug shows up, when it's there, it's there for every URL, within and beyond any specific domain.

@yanta wrote above that the problem occurs regardless of standalone installation and hardware acceleration. And while I assume it will not be any different for me, next time the problem shows up, I will install standalone opera and give feedback.

@panosv
Indeed they do.

I was in deviantart, and just noticed the plague is back yet again...

@panosv
Since one or two days after my last report, I have not experienced the bug again. Since I'm afraid of possibly triggering it again, I'll stay away from testing the dark "theme"

Update: the terminator is back

It is night over here, and I have not noticed the bug at all the whole day. I wonder if the latest update fixed this.

@panosv

But no other single application (that has tabs/stuff on the titlebar) on my system suffers from this. Also, Opera, like any other software, has suffered from serious bugs throughout the years, and many bugs which have only affected SOME users and noth others. For example, one bug that affected me badly was when my speeddial was vertically a multple (2+) of the (browser's) display area, then whenever I expanded a folder and restored again, the view position was always reset to the middle of the speeddial document. If that would have affected all people we'd read about it. Yet I never read anyone else having that problem, but when I insisted this was happening to me (filed a bug), it didn't take too long for the devs to fix.

Back on topic, I'm not familiar with the code that deals with miximized/restored windows (or anything else for that matter) to claim anything. It may or may not contain bugs. I personally incline towards the former. And I'm sure that if they look into it they'll find the bug(s).
Also later today, and during a few days, I'll be using FF inclusively to evaluate whether this is an Opera bug, or a Win7-32bit-sp1 / driver bug.

@panosv said in After full screen, the tabs lowering:

@eternal1

after returning from fullscreen I realized the menace is back.

With dark theme? Because, as you said above, your hardware is old (as mine on 2nd pc), and maybe the Opera (and other Browsers) is match more with the new hardwares.
Maybe, i'm not sure

I really can't stand the dark theme (I hate contrast between brighness (pages) and darkness (browser GUI)) beyond a certain level, to keep using it to evaluate whether the bug occurs then as well or not. Nevertheless, I doubt very much that this is anything beyond just a simple Opera bug. I don't remember firefox having such bug, and neither did opera for me until some weeks ago, so it's not like I installed new drivers or even updated windows that triggered the bug either. Some code change in Opera definitely caused this.