EDIT:
It works now.

In Firefox I have disabled "Enhanced tracking protection" for gog.com (in the address bar) and made gog.com an exception for pop-up windows in settings.

ORIGINAL POST:
Hi,

Whenever I try to wishlist or un-wishlist anything the website asks me to log in.
I am already signed into my account. Signing out completely and signing back in makes no difference.
Each time I click on the wishlist button the log in window pops up.

Does anyone else have this issue?

Any help would be appreciated.

Some more details
I am using Firefox and my OS is Manjaro KDE.

Have you tried to reset (or delete) your GOG cookies? Or to change the browser?
Maybe refreshing your GOG account will help? https://www.gog.com/user/refresh

Browser or GOG Galaxy?

The page resources aren't loading all the way I'm guessing. Connection problems (time-outs), or security blocks (router / firewall) or ad-blocking extensions on your browser could be candidates.

Browser. I'm using Firefox and my OS is Manjaro KDE

No mention on whether an ad-blocker or any extensions/add-on's are being used ?.

Have you tried anything from my previous post?

I tried that but it didn't work.
My adblocker is also deactivated.

In Firefox I have disabled "Enhanced tracking protection" for gog.com (in the address bar) and made gog.com an exception for pop-up windows in settings.

It works now.

Well.. what version of FF are you using? I have this protection turned ON and no exception for popups.
My wishlist still works without problems on FF 91.10.0esr 64-bit.