BTMM - iCloud server not responding

I know that BTMM is being deprecated in Mojave but I've not been able to get BTMM Screen Sharing to work in High Sierra 10.13.6 for the past several days. iCloud System Preferences reports 'iCloud server not responding.' under Back to My Mac at all of my remote locations which all use separate ISP's. Un-checking then re-checking BTMM doesn't resolve the issue, it just beach balls System Preferences for several minutes before returning to the not responding message.

I received a notification from Apple that I can use Apple Remote Desktop for screen sharing instead which I just purchased but there is no clear way to connect to my non-local computers.

They all have Remote Management enabled and are logged into iCloud using the same AppleID. With BTMM, all of my remote machines were in my finder shared list, no additional steps were required for them to show up. With ARD, I enter the remote IP addresses and the scanner sees nothing.

I need to be able to screen sharing over the internet again, any insights into this issue would be appreciated.

Peter