As requested by Garmin-Kevin, I am putting this in a separate posting for bugtracking:
Intensity minutes calculation for indoor swimming doesn't make any sense on the Venu 2.
In my case it displays an average heart rate of 160 for a 33 minute swim, but only counts 3(!) high intensity minutes and no normal intensity minutes at all. See this screenshot:
This is not a one-time glitch, it has happened with all swim trainings I tracked with the Venu 2 so far. Maybe it's a problem that is limited to the 50 meter pool size. I haven't had the chance to use a 25 meters pool with the Venu 2 so far.
Please check into this issue, since it makes the Venu completely useless for swim tracking at the moment.