Those alerts are based on average usage over a period of time, and are sent infrequently. If you are getting them more often than about once per week, something is wrong, and, even if they are coming once per week, if you’ve never had significant usage, then again something must be wrong.
If however during initial set-up and testing you used it a lot, this could still average out over say the last two weeks, and represent usage higher than their recommended best battery life usage, and could have resulted in say two alerts, once per week, because you are still above ‘average’ for the periods in question.
If the former, call support. If the latter, wait until next week and see.