I bought Assassin’s Creed Origins on Steam and purchased one of the DLCs on Uplay because it was on sale. They told me after it wouldn’t load that no the DLC wasn’t compatible because it was bought on a different storefront even though they both ultimately run on Uplay…

No I couldn’t get a refund either…

I now view it as a personal risk to give Ubisoft any money whatsoever so I have zero qualms about pirating their games.