I'm using "space traveler" watchface by Garmin (apps.garmin.com/.../60e80875-abeb-4167-a525-866eafe95126 ).
Starting with last 15.19 update I frequently see "no gps" in the sunrise / sunset fields.
It disappear if I start an activity (but it's not required to do it), but comes back randomly.
I'm registering a full activity almost every day, but I've got this issue many times and never with the old firmwares. Already tried to reinstall the watchface.