I have the exact same problem, I am trying to create the Achaemenid Empire on the Mediterranean map and it has split so much that I save after every turn just to see if I can go back and get a better card instead, and to undo the split11111111!!!!!!
Edit 1: The Achaemenid Empire just lost all of Türkiye in one split...
Edit 2: The Achaemenid Empire nearly controls ALL OF ANATOLIA!!!!111!!1!!1!!!