I believe this is a bug but it may be a (removal of-) "feature" update. A watch face of mine used to update altitude in semi-real-time when onExitSleep (low power mode disabled with wrist gesture) is activated using:
var altitude = Activity.getActivityInfo().altitude;
...and then printing on the screen.
More recently however I have noted that on a Fenix 5x watch with firmware 12.30, the value does not update until a full minute has passed. This is true even if the user re-calibrates the altimeter. and returns to the watch face.
I have run some tests with a totally bare-bones code and i get the same result (controlling for any other potential pitfalls). furthermore, the code runs in the simulator version of the same watch correctly and when low power mode is disabled.
my other option of Sensor.getInfo does not work either as Sensor is not available to watch faces.
any suggestions?
thanks!