My Windows 10 machine couldn't go to sleep or go to screensaver. Quick check found that the GOG Galaxy process had a video wake lock. Opening the client and closing the winter sale animation banner released the lock and now the computer can sleep.

Placing here for anyone searching the forum for a similar problem.

I noticed this too!

C:\WINDOWS\system32>powercfg /requests
DISPLAY:
[PROCESS] \Device\HarddiskVolume8\Program Files (x86)\GOG Galaxy\GalaxyClient.exe
Video Wake Lock

After closing the winter sale banner:

C:\WINDOWS\system32>powercfg /requests
DISPLAY:
None.

Same here. Was wondering why my monitor stopped sleeping.

OG just earned itself a paddling.

Also happening here. Hopefully this is corrected properly soon before monitors start to get damaged.

Wow - quick troubleshooting there @bobjhon!

Just found out about the "powercfg /requests" command today and also saw GOG was the culprit with my monitors suddenly not sleeping. Didn't even think the banner would be the issue, but yeah, totally it!

Hopefully GOG sees this and fixes it...you'd assume it'd be an easy thing to fix since you've already narrowed it down to a single banner.

This was happening to me too. My displays have been on for 72 hours straight thanks to this and me thinking I fixed the issue some other way. CDPR has shortened the life of my expensive gaming displays with this.

yup, i have the same problem. luckily closing the winter sale animation with the x, lets it stay closed and "fixes" this.

still, annoying wondering why suddenly your screens wont turn off when idle. hopefully they fix this before the next sale with a video banner.

Hotfix 2.0.45 that addresses this issue was released December 21st. You should get the update prompt if you leave GOG Galaxy running a few minutes. The offline installer has also been updated.