After resuming Garmin Coach Plan I got error in app like "Something went wrong". In web app I narrowed error listed below. I think it started after second resume in the next day. Try this steps to reporoduce:
1. resume after while (in my case it was 2 weeks)
2. pause same day
3. resume next day
Error comes from this endpoint: ...garmin.com/modern/proxy/workout-service/schedule/:id