Can you put a ticket in with the support team - they’ll probably need to get your save files - it should show up once it meets the criteria to make a valid team (eg 23 players on the roster)
There’s two aspects to stamina - the “sprint” and the overall stamina. So the sprint is what you’ll see drain away, the boost run from the trigger. If you’re more sparing about when to sprint before you get to the gap you can utilise it more.
That said, it’s certainly something to balance, especially relating to the AI to ensure that anything that’s normal rugby isn’t penalised with draining sprint too much, at least for players with good enough fitness stats.