I tried to do a Tour de Zwift ride today and spent about an hour opening/quitting the app, reinstalling it, and then talking with online support because I’d end up in a group ride but no other riders would load in. After looking in the Zwift logs, I found a bunch of these errors:
NETWORK:error (8) sending player state
which led me to realize I had left my work VPN on and it was blocking only the packets required to do group activities, but not the ones to load up the app.
It would be really great and would have saved me a lot of time if there was a popup in the app that said it was having trouble connecting and to check VPN/Firewall settings instead of just looking like it was trying to load other players in indefinitely.