Hey zeddieeee,
If you've purchased the Season Pass on Uplay, but the base game on Steam, the content is incompatible. We have an article here which warns players against buying DLCs on a different platform for this reason.
If you did not purchase the pass directly from the Ubisoft Store, I'm afraid that we're unable to process a refund or assist further, as we are not your retailer. My best advice would be to contact your retailer to see if they could offer a refund for the incompatible content.![]()