Upon earning my 21st Era Star, the game notified me that this was my last turn, and indeed the game ended the next turn. That happened despite the fact that I earned only 21 Era Stars out of the new limit of 24 (21+3 Diplomat stars). My "winnning combo" was earning gold in every category except science (1 star) and diplomacy (2 stars), though I'd wager that earning 21 stars distributed by any way within the categories would end the game.

I'm not 100% sure that this is a bug and not an intended interaction (I didn't get the "The Stars My Destination" achievement for winning the game that way), but if it isin fact intended, than it should be communicated more clearly to the player.

My guess that this is in fact a bug, and the win condition for earning all avaliable stars in the Contemporary Era hasn't been updated to include the Diplomat stars.

See attached: screenshots and a autosave file (start of the last turn)

Screenshots (direct image upload not working for me at the moment)

auto-save turn start.ctr