This is a usability thing more than a bug (hopefully not a daft user error) but the inflexibility of the dating of workouts is an issue...
If in your exhausted post deadlift state you forget to hit the big tick at the bottom to Submit a workout, the next time you might be prompted to do so is two days later when starting a new workout. So you hit the tick to save those numbers, then hit "Today's Workout" to get your sets up... but no! You've already worked out today! Aaaaargh! No problem, we'll go back into the Workout history and adjust the dates so the app knows I last worked out two days ago... but that doesn't work either? I can change weights and reps and all sorts, but not the date?
This lockdown also frustrates a little in that you can't "peek" forward to the next workout - I know that generally it's going to add 2.5kg following successful sets across, but it's a mental thing to see it, start preparing your mind for that next jump.
Using iOS version 1.1849