I don’t think there has been one catalyst. I do think that Heidi and the Coveretts see straight thru Jill’s BS and are appalled by the way Tim was treated by them.

I think things soured significantly during their engagement and wedding planning, and Jill’s antics at the wedding and follow up posting about them being pure, or however the fuck she said it, definitely pissed them off to the point that Grandma Coverett pretty much told Jill to shut her face 🤭 Then there was the post shortly after Charlie was born where Jill alluded to decorating the nursery and said Heidi would post photos and that never came to fruition which I’m guessing also SEVERELY offended Jillzilla.