Many of the displayed parameters on my watchfaces depend on GPS, including: heading, speed, distance to home/base, altitude, longitude/latitude and compass indication.
Garmin does not provide watchface apps with a way to turn on the GPS unfortunately. On most Garmin watches an activity like a run or walk must be started outside in order to turn on GPS. Start an activity, and once GPS is ready you can switch back to the watchface. On the GlobalSync and Worldtime Diver watchfaces, the longitude dot indicator will be green indicating GPS available. On the Aerospace+H watchfaces the GPS signal strength indicator will appear. After this, the parameter should update until GPS signal is lost or the GPS is turned off. The watchface will remember the last known position for distance to home/base and longitude/latitude display, as well as for acquiring weather data.
Some Garmin watches have an “Auto activity start” setting when turned on will automatically turn on GPS if it detects you are walking or running for a while, and when this happens the compass heading indicator will appear.