Enable the "Ambient Pressure" field in a data screen in an activity (NOT the "Barometric Pressure" field). What does it say?
Let it run for ahile without restarting (may an hour). Does the graph start getting data?
I've experienced a few weird issues installing Spotify, but after about three days, all my sensors and Spotify seem to be working. It actually took me three days to actually get the sync to not issue a Sync Failure message(another user mentioned the same). In that time, I saw Spotify say it was syncing 1 small playlist and running the watch dead, the watch completely locking up. At one point while trying to uninstall the app, I could not get it removed via Garmin Connect(Uninstall Fail, in RED, was the message I think), and had to use Garmin Express.
I checked all my sensors, and all seems settled and working at the moment. I'm afraid to touch it now.
I have set these 2 options for pressure in activity mode and none of it works.