Betrothals constantly getting broken

[BD13]

I am really struggling with broken bethrothals. The majority of betrothals I set up are getting broken. Usually by the time I notice it's too late and the original spouse to be is set to marry someone else.

Seems that a change in the guardian breaks bethrothals. Not sure if this is a bug or WAD. Anything else that cancels bethrothals?

 

[FifthMonarchy]

I think something is bugged with betrothals as I have had a few instances where I've made onel then gone to suggest an alliance only for a message to pop up saying the NAP has broken down as no longer any ties. The betrothal will be broken but the AI will happily accept it again (and usually the alliance too second time, when it seems to stick).