I've had this issue for as long as I can remember, possibly since Dec. 2019 when I first began using Galaxy 2.0. It's the primary reason that I've not used it in day-to-day gaming. It happens long after I've launched Galaxy 2.0, at least 10 minutes to over an hour afterwards, and it reoccurs during the same session. Ahh.. that makes me wonder if it's related to my unorthodox dual display setup. My main display is a 4K HDR TV connected via HDMI, and in Windows' settings I have its scaling set to 200%. I have HDR disabled where and when it's possible to, but it does sometimes enable itself when launching certain apps. My secondary display is a 1080P non-HDR PC monitor connected via DVI, and its Windows scaling is set to 100%. My guess is that the 200% scaling is causing an issue, but that's just a hunch based on the fact that it can sometimes cause other weird issues.

My setup is otherwise straightforward: Windows is kept updated automatically, I don't have any third-party security software, and I often use Nvidia GeForce Experience's overlay/game capture a.k.a. ShadowPlay.

that is an easy senario to test at least
try disable \ unplug one screen and fire up your Galaxy \ game for an hour or so... if the issue goes away then you have your answer mate ;)

I use a single monitor and it still happens. It's ultrawide, but other than that there´s nothing unusual in the config. (100% scaling, no hdr)

Also, I said earlier it might be related to gog notifications... scrap that, last few times it happenned there was no new notifications.

I have suffered this issue too. I have no dual display, no fancy stuff, just plain Windohz and some (mostly old school) games.

For me it was horribly annoying when playing No Man's Sky - after going to the background that game becomes unplayable (laggy like a fly in tar). The only solution is then to turn the game off and start it again. With NMS, however, you cannot save whenever you want, and starting the game takes a few minutes. Reminds me of the times when games were loaded from magnetic tapes. :-/

Anyway, I second that sometimes (most of the time) after Galaxy took the focus, there was no message, no notification, no new update in the list. No visible reason at all. And no reliable way to reproduce. I believe it was happening mostly once a day, at random times. But for more than a week or a few weeks. Currently I'm playing Kingdom Come, and I believe to have seen the issue only once. With NMS it was much more often. Somehow I doubt that it depends on the game, though. Maybe it's just that with other games the problem is not so annoying, so I tend to forget it.

Hello there,

Same trouble with Galaxy 2.0 - a forced desktop return happening during games, exclusively when Galaxy's running in the background - and it has been bothering me for a few months. I suspect it began with the last update (since I don't remember witnessing anything in early 2021), but that's just a guess. Since I don't use Galaxy on a regular basis, I took me some time to connect the dots and understand what was going on, mostly by using windows's Event Viewer.
In my case, like Arsen's just above, there's no fancy stuff : no dual monitor, no TV or Iphone connected ; no screen software - it's even happening on one of my old horses equiped with a CRT lol ! - or anything uncommon. It concerns both Windows 10 and Windows 7 x64 (which didn't cause any noticable trouble with Galaxy 2.0 up to now, as far as I'm concerned). But every hour, according to the Event Viewer, GalaxyClientService kicks in - for whatever reason, I don't know - and shortly after, that weird (unknown) focus reduces my current game to the taskbar. Whether or not it is a coincidence, the said trouble does happen precisely every hour... Which isn't that annoying when you're playing X-COM 2 : Terror from the Deep, turn-based, but completely screws you if you're in a fast competitive (non GOG-related) MOBA game : 5 or 10s lost, with that forced sudden alt+tab, and you've obviously just shot your team in the back...
I first suspected an issue with one of the Visual C++ 2019 packs, which Galaxy started to require after that last update (in preparation for future ones apparently), because that one caused at first another problem - restore points created every hour for apparently no reason, which obviously meant the loss of every previous point I had asked for (manually) in a day or two -, but reinstalling manually the latest 2019 package fixed that.
So now, the only clue I'm left with in the Event Viewer remains that GalaxyClientService activation every hour, even though (after all) it might be something else : other users seem to be affected on a less regular basis... Any hint or idea would be greatly appreciated !
Even though it's not that bothering after all : as long as you stop running Galaxy in the background - and kiss the achievements goodbye. Which was more or less the only reason why I used Galaxy unfortunately... -, everything seems fine.