The Lilith dlc claims to be free but it goes to Xbox store for $20 on borderlands 2 (this should show the issue) but if you won’t watch it the gist of it is that the commander Lilith dlc is claimed to be free but redirects to Xbox store for $20 dlc

It was free for a limited time, then priced.

This has been brought up before. The in-game information didn’t get updated when the free period ended, unfortunately.