Ahhh, I think that’s it…thanks for the pointer!
Same problem for me! Roon Arc was running fine , after update Roon my Android phone couldn t find Roon Arc anymore
Sorry, I have no idea what that means. 
Thanks for the link. Unfortunately, it’s still a bit over my head. It seems to be referring to IPv6 just being used within the local network. But when I do the test linked by Roon, it seems to say that I have internet access using IPv6. I guess I’m still not understanding.
I don’t wish to derail this thread further (I’m not using EA), so I don’t expect to be educated about this here. 
Does your roon server still confirm a successful connection to the outside world (Mine does not)?
If that is the case and simply your phone cannot reach the server, it might be due to the issue that something has been renamed. Deinstalling and subsequently installing ARC and going through the identification process again, usually helps.