it's not so bad.
Most of the time, probably not.
But in my case, Venice, who Serbia handed off Epirus to, has a monstrous network of allies, meaning I can't take it back. What's worse is, they're now fabricating claims all over Greece.
None of this had any reason to happen, except for a broken game mechanic.
I can't help but imagine Byzantine soldiers returning home from Crimea, only to find Venetians garrisoning the fortress.
"What are you doing here, this is our fort, leave!"
"Your fort? This is our fort, we just got it."
"What? Who gave you the idea that you could just walk in here and take over, unopposed?"
"Serbia."