Whoa!  :O

Between "Expel Forces", the ultimatum action, and the action that reduces the other player's war support (enough to force a surrender), it looks like there are so many unintended consequences using embassy actions immediately after a war ends that maybe there should just be a 5-10 turn cooldown on any embassy action after a war ends.

It could be quite a long cooldown in fast pace games, so it might need some tweaking.
Agreed on the idea.

The turn counter could be dynamic to game speed if needed, yes...  but now that I think about it, I think War Support changes are one of the few things that aren't dynamic with game speed?  If War Support gains/losses (ongoing or instant) are constant across game speeds, then the cooldown would probably need to be constant too, to give the right breathing room.  *thinking emoji*

Or maybe limit to 1 trespassing grievance regardless of number of armies.

With the current behavior I guess the correct action was to wait for 10 turns for his extra grievances to expire before rejecting his 1 demand. (which would still generate 5*8 + 3*10 = 70 war support in 10 turns, before accounting for war support under equilibrium and influenced territories).

But at least I would have had 20 war support by then. If he declares war now, he could force a surrender.

Ansive wrote:
Or maybe limit to 1 trespassing grievance regardless of number of armies

That would also work pretty well, yes.

Are you sure, expel force is needed ? I'm pretty sure I get this grievance without using the embassy.

Just because their troops were in my territory at the end of the war (because of sieging an other city probably).

And after few test, I see we can't use expel force against an expansionist empire or an empire without open border. So I guess it's really just the trespassing army at the start of turn.

In my case it's the embassy action. (the liege normally has open borders with their vassal)

I'm also able to use it versus my vassal and get grievances.

Another solution (other than a hard cooldown) would also be to make an action more expensive for X turns, like the diplomatic proposals (which cost extra influence for 5 turns).

Running into prowlers (ambush) also allows warfare between liege and vassal...

Ansive wrote:

(the liege normally has open borders with their vassal)

hoo. ok. indeed. I though you got peace with this enemy, not vassalize it ^^"

Hello!

 
Thank you very much for your report :)
The issue is being investigated. 

Have a lovely day! ^^