I'm moving a website but keeping the email setting for now, so I changed the A Record on the current ISP to the new IP provided by the new ISP. And it has been more than 48 hours the domain is still flipping back and forth between the two IPs.
I've kept an eye on it on https://www.whatsmydns.net/ but there's no real progress in the last 24 hours - sometimes I get only 4 servers showing the old IP sometimes I get 12.
Contacted both ISPs, both suggested just to wait longer, but this is very worrying.
The old IPS is TSOHost - previously Vidahost, so don't know if that's the problem.