Here is the popover working normally.
Have you updated FM14 and FMGo? There was an similar issue with some fonts and the update I believe fixed the missing font issue.
I would update FM14. I guess opening the database and resaving it in FM14 will apply the update to the database. I'm not sure if you will have to recreate the popover. For that matter it may not be a related issue. Update FMGo to the newest version.
I would do the updates and test and if you still have the issue then I suggest posting on "Report an Issue" at top of this page. FMTS may want you to send a copy for testing.
I updated to the latest FMGo with no improvement. I'm developing on FM13v4 and will try updating to the latest 13 version next. The problem is intermittent and when it works it can go back to not working minutes later. All of the layout fields etc are on top of a big graphic .png image used as a background-- I will take it out and see if that is causing the problem. There is also a script trigger on the popover that fills in a field on the popover -- could be something with that.
I'm seeing this quite frequently across 3 different iPads all running FileMaker Go 14.0.2. Happens at random times with multiple popovers on different layouts - all of a sudden you open a popover and it's completely blank or only showing some fields. Usually you either have to navigate to different layouts or close the file and open it again.