Title. No "Claim NOW" button on the banner in my GOG Galaxy, other people posted screens of their banners and mine is just missing the button for some reason.

I own regular edition and GOTY edition on GOG, account is linked in settings
See attached image for banner image

list all the platforms you own witcher 3 on

Just GOG, so that's the only thing I have linked

then theres nothing for you to claim. you need to own the game on another platform than gog

I own both the standard and the GOTY on PS4. I have synced my library and the games appear but there is no Claim option anywhere. No banner. Nothing.

Any ideas?

I have the same problem (ps4)

Well, the banner does not appear for me either, and i own both the standard version and the goty version on ps4.