I use Zwift on my IPad and Compagnon On my IPhone.
Sometimes Compagnon loose the connection with the workout.
Sometimes the connection is not established.
In those cases, how can I restart the connection with the workout on the IPad?
In order for the Companion app to connect with the Zwift game, both units need to be on the same network. If you are using the Companion app on your phone, it is possible that your WiFi connection is not good, so your phone is switching back and forth between WiFi and cellular data. And when it switches to cellular data you will lose the connection to the game. So, you might try turning off the ‘WiFi Assist’ option to see if that corrects the issue.