Even my bank doesn't do this. Any way to stop this nonsense?

Select the "Privacy & settings" entry in the user profile menu, and then go to the "Login and security" section. You can disable 2FA there.

Stay logged in?

Ask GOG to implement a proper 2FA?

I would really recommend NOT to disable 2FA. And I would switch my bank.

@fe79 thanks! Found it.

Oh man, thanks for the info. This 2FA drives me crazy. Why can't I authorize MY OWN PC at home once for good? I'm the only person accessing GOG from this PC. This kind of 2FA protects my account from being accessed by myself, really.
Finally disabled this nonsense.

Yes, you can authorize your own PC at home. That's what cookies are meant for. But let me guess: You set your browser to delete every single cookie on exit because somebody told you they were used to "spy" on you?

If instead you keep GOG's authorization cookies, you can stay logged in for a very long time. Despite active 2FA, I can't actually remember the last time I had to do a login myself, must have been almost a year.

Disabling 2FA is a security risk. It hurts you more than it helps you. Because it enables random people on the Internet to try and brute force your password. They don't need access to your PC for that.

Nope, I don't delete cookies at home. It normally works for other sites without ANY issues.
The only site I have to re-type the authorization code is GOG. This isn't very pleasant.

Then you are doing something else wrong. Because authorization *does* normally work just fine.
Could be anything, really. Adbocker, firewall, privacy protection, site-specific settings, browser plugins/extensions etc.
But it is pretty clear that you've already made up your mind. No point in trying to help someone who doesn't want any help.

What browser and operating system? You haven't installed any extra adblockers or stuff?

For me it works exactly as g2222 said, if I use e.g. Edge or Chrome/Chromium with default settings, which means they will not actively delete existing cookies etc.

Don't log out of your GOG account either. When you are done, just close the browser, and the next time you open the browser and head to gog.com, you should be right there logged in already. I haven't tested what happens if I log out, but I don't think it should trigger 2FA if the cookies are still there.

It's still something on your end. I was logged into GOG permanently on my previous computer, never had to do any authorization even through OS upgrades over the years. The one time I had to do any authorization was moving to a new computer when I reinstalled everything from scratch, and I've been permanently logged in since then (last year). Whatever GOG is doing I wish other sites would do, since most seem to log me out eventually, though it might take months or longer.