Zwift on my Samsung S5 worked perfectly for weeks. One day, it degenerated into only working intermittently, to the point of it being useless.
It turns out that Android (annoyingly, in my view) automatically battery-optimises any App that has not been used for three days.
Go to Settings, Battery, App optimisation, Detail. If Zwift has a been optimised, tap it, and disable optimisation.
How did it manifest? I am having a weird problem where after about 10-15 minutes I lose the turn buttons in my android app. I’ll try to turn off the battery optimization idea to see if it helps.
That was indeed one of the manifestations. Another was all readings on the main screen (heart rate, cadence, power etc) freezing. Changing the view would “restart” things for a short while. It’s all a distant memory since I turned off battery optimization. I hope it works for you.