The my rewards section keeps saying "error log in with Galaxy", I am logged in with Galaxy, I'm not using any mods, I've done a clean install and that did not work.

Google only comes up with this issue and no solutions.
Any help would be appreciated.

I'm having this issue also. I should have searched before I posted a new topic.

I have the same here. I uninstalled and reinstalled the game. But no changes. It keeps telling I'm not running from GOG Galaxy.
Plus the cloud isn't working at all so I can't pick my save from my ps4 to play Phantom Liberty on my pc. --"

EDIT : Ok guys, go to "parameters" on GOG Galaxy and click on "synchronize integrations". It worked for me !