I wish I had seen this earlier.... I did the exact same thing with my Danes campaign the other day.

I save every 10 minutes, and my loyalty dropped after I used my king to attack the Irish, and without fault I had loyalty drops and a civil war.

Interesting we had that same problem at the same time nearly, except mine happened about a week ago.

I'm happy you figured it out, I did after pondering for a while.

Welcome to the Org!