This is the same bug I posted 2 years ago (which is now locked).
When you do a row activity, if your speed ever drops to 0, Garmin Connect will graph it as infinite pace (the fastest possible) instead of graphing it as the slowest pace possible.
Unfortunately when I submitted the bug to garmin the support team and/or engineering team fumbled it. I was trying to help them reproduce things, so I explained that this bug only happens for rows and not for runs. And I showed that if you convert the row to a run the issue goes away, the pace is correctly plotted as the slowest possible. And their response was "why do you convert your rows to runs, is this something you do regularly?". And they fllagged it as an issue that only happens in weird circumstances when a user converts a row to a run... Painful to say the least.
I tried to update the ticket to explain that this happens for *all rowing* activities but I feel like I'm speaking past support; they have yet to acknowledge that they understand what my issue is.
Anyways if you do rowing workouts, it would be great if you could submit this bug as well! Not the biggest issue but definitely a bug.