I had another crash on a custom workout (one of the University of Toronto study workouts, possibly relevant to @SpareCycles 
). The workout got to the end of what I think was technically the “warmup”, and crashed after I heard the “next interval” beep. When I restarted the app, the workout had been saved, and I was not prompted to resume.
Moto X4, Android 9, TR 2020.36.0.92034