This happens to me too. Series 0. I can leave it for however long and it won't show anything other than the grid.
Odd thing is it shows the map properly when I search locations or POI's though. Just not when I tap on "my location" first. If I search directions so it shows a destination (and the map is displayed), then I tap on the arrow to show my location, it'll then show the map properly. And will then work if I back out and tap on the "my location" option.
Hopefully it won't happen again. I am a developer of a maps app for the watch, so I use maps on it a lot and I have only ever seen it once. It seems to get into some state where the map just won't appear. I tried rebooting both the phone and the watch but to no avail, so I eventually re-paired it and that fixed it.
I wish I could say that it will definitely fix the problem and that it probably won't happen again, but I can't. All I can say is that I use it a lot and it's only happened once for me, and that re-pairing it fixed it. Hope that helps.
[doublepost=1492135267][/doublepost]I've had my Apple Watch 2 weeks and the map worked for the first week. Since then I only get the grid. I've unpaired, repaired, rebooted and only the grid appears. Actually getting tired of Apple's crappy products, inferior packaging and lack of service and responses