Roon Server not running randomly

Hi Guys,
Had no end of issues only with Roon (no other programs) after changing ISP. The latest one has saw my Roon Server unable to be found by Roon. All working fine for 2 weeks then this.
Anyone help?

I take it that your new ISP supplied a new router.

Are you using this new router? If so, the following questions may be relevant:

Is the local network subnet created by the new router the same as that of the old router?

Was your Roon Server configured to use a static IP address? If it was, and your new router creates a different subnet, your Roon Server may have an ip address outside of that subnet and thus become unreachable. If this is the case, then you will have to change the ip address of the Roon Server to either use DHCP to obtain an ip address or change the ip address to one in the subnet created by the new router.