I've been seeking for this problem resolution for weeks already (as soon as I got my F5X) and there's been no resolution yet.
The face developer apparently works on the watch emulator only and can't fully reproduce F5X environment (not to mention that the current firmware is still buggy).
All we can do is just to wait for the next update. As you can see the update request appears in almost every comment to the creation and many people (including me) has already sent a begging message to the developer urgin him/her to keep on working on the face update.
GearMin is the face I want to use too (I use it on my FR935) but as well as the issues you mentioned, real time Heart Rate data is also failing to display on watch faces.
You can even find Garmin made watch faces on the IQ store that should display HR and they don't.
I've just tried this new beta firmware and the issue is still there.
The most odd thing though is that when you go to the watch face selection screen, the HR is actually displayed and updates just fine; it's only after you actually select the watch face that it stops working.
Apparently it was mentioned by the devs at the developer conference thing they had recently, so they know about it. But why it's not getting fixed I dont know. It makes me wonder if it's a hardware issue (and makes me wonder if I should just return the watch to be safe).
As an aside; the chap who develops GearMin has apparently ordered a F5X so he can properly attempt to fix it (although I'm not sure if he can without Garmin sorting out the issue first)... because he was sick of getting 10+ emails a day about how his watch face doesn't work on the 5X :)
It's not just the GearMin watchface which isn't working properly.
Many watchfaces in the CIQ store aren't working properly, some won't even load and switch to the standard Garmin one after selecting.
Many people have complained about this here in the forums - even more in the Comments section in the respective Watchface/CIQ store sites
As someone stated above, I'm also considering returning the watch.