Carthage bug?

I play my first game as Rome.
The settings is VH/VH.
I have taken lands in Sicily, that was rebel. That was a declaration of war. (I had an alliance with them)
But they are hardly pressed from all sides, and i made a peace offering - Ceasefire, trade right and a demand of 5000f - They agreed very happy.
Next turn WAR! I then made the same diplomatic offer, they accepted.
After 6 turn with this war - tribute - war, it got old real quick and my reputation is very untrustworthy because of it.

Why does Carthage do this? is it a bug or because of the agreement of not entering each others spheres ?
Please help me with this.

Scripted declaration of war over Messana. There's an announcement that pops up when you take it.

Which cities you have in Sicily? After you take Messana (and hold it), the script shouldn't force war between Rome and Carthage anymore.

Yeah i got the message, and i understood the consequence. but every time i ask for peace (and get a little tribute) war is on next turn. i took Messana in turn 40. at turn 70 i got so annoyed i took there city on Sicily. And now, turn 110, its the same. Is there any way for them to accept the loss or at least invade the out of me..

I tried this myself, and indeed you can't get the truce to hold with QH after taking Messana (got the warning too). I gifted Messana to Numidians and Lilybaeum back to QH, but no effect. I force ceasefire, and when next turn begins, the war is on again. I suspect the script isn't working as intended, and forces the war even when not intended. I looked at the script (I'm by no means a script wizard) and one possibility might be that the counter RomansNearMessana gives value 1 even when it shouldn't. Perhaps someone much more qualified might take a look at it?

edit. There's something shady about the x and y positions in the script too. Messana is positioned 142,137, and the script uses two different values: near 143,137(1 tile east of Messana) gives the warning (this is OK), but the locations that force the war are tiles near 147,137 (5 tiles east of Messana -in Brettia). This means Roman army can stay indefinetely near Messana without starting a war (tested too).