I am having this same issue. I have narrowed it down to a problem with GOG. I added Steam, Epic and EA one at a time with no problem. They each gave me the list of all games on each store front. Every time I try GOG it give me the same message as you. When I log Out GOG, everything is fine.
So you do not have to turn off Auto import if you would rather have it on.
Would like some help getting GOG up and running though.