So I actually had this exact issue about a month ago.

Solution: You have to connect to chromecast through your phone app. However, the jellyfin app have to be installed through play store. If you install it through f-droid or similar it won’t work.

Took me about a month of troubleshooting to find that answer. :D

Does that include videos?

Mindbug - an amazing card battler for two without building a deck. The twist is that you can take the opponents card twice a game. Makes for a super interesting gameplay.

Splendor duel - seen it mentioned before, a really great implementation of the splendor game for two