I took the below paragraph from another post in 2020. I have this exact same problem. This morning my internet connection was goofed up and then resolved itself (maybe Xfinity had a problem but I don’t know). And then this Roon problem appeared. I am not a network person so not sure what I can do to my network to resolve this if that is the problem. I have rebooted all devices (MacBook, iPhone, iPad, Roon Core) and tried other endpoints, Roon on my iPhone and iPad and they all do the same thing - time bar just bounces from side to side.
I have access to my library, Roon loads the songs I want to play but all that happens is the time bar under the song title bounces a blue line from side to side and the music never starts. I have the same issue on both iPad and iPhone, I have reloaded the apps on both as well. Any thoughts?