Setting on mobile is to have notifications pushed to my mobile if inactive on desktop. So far I've never received any notifications on my Android phone.
Justin Sevier commented
Agreed. Android user here as well. Trying to convert my org from Slack to teams but the lack of intelligent push notifications is killing the transition. If the user sets to always notify in the app they get it, but it's like the inactivity sensor isn't working to identify when push notices should be sent when only when inactive is selected. Happy to provide more info to run this one down as it's critical to our org.