Ok. Go to Advanced DNS manager of Control panel. There will be all records written as A, AAAA, CNAME, etc, you need to replace with same at Cloudflare DNS. That should fix. If you don’t need e-mail stuff, just update A record IP. I think much better this can be done from someone who is experienced about DNS management, probably that is your hosting support team.
If you are not technical enough, here’s an alternative way
Switch to hosting provided nameservers for 1 day.
Remove domain in CF.
Add it back, while this process I assume it would fetch new DNS entries.
This has all been running before, so the only change that should have been needed was changing those said records to the new IP address provided by new Hosting company… yes?
Hosting company has advised me that the propagation to CF did not work, so they are running it again.
So just have to wait, again to see if it works.
Thank you for your alternative advice.