In the SDK Ver 8.1.1 simulator,
AppBase.onSettingsChanged() is not fired in a data field app when settings are changed from the settings menu (of the data field).
On an actual watch, it appears that the data field settings can only be edited when the data field is first added to an activity data screen. When the activity is ALREADY RUNNING, the "Edit data field settings?" screen shows when the data field is selected but "Yes" cannot be selected. The only way I can select Yes is when the activity is ALREADY RUNNING, is to remove the data field from the data screen then add it back, and when that is done I can select "Yes" and edit the settings.
Is this the intended behavior? If so, why can't settings be edited on the watch during the activity?