Questioning my low VO2Max reading

Hi there. Not question this from a standpoint of ego, but genuine concern. I am not a crazy athlete, but am very active. I am heavier set, in my 50s but ride at least four Peloton workouts a week as well as weights and regular extended walks. I often do a full hour on the Peloton with some challenge trainers, but then I walk outside on a short 3km walk my low cardio fitness warning on my watch comes on. I was hoping it was my older watch not reading well but upgraded to series 7 yesterday and same reading.

Stumped. These tools - like the apple watch - become valuable data sets (and are marketed as such) so hopefully we can get some decent answers as I have seen others pose similar questions. Thanks all!