Are you testing this in FileMaker PRO on a computer or in FileMaker GO on an iOS device? (This is the FileMaker GO part of the forum).
What you show looks like the standard appearance of a layout in FileMaker Pro when the layout has been opened for editing by putting the focus (cursor) in one of the fields of the layout. It can be prevented by by going to layout setup and clearing the the "show field frames when record is active" check box.
Thank you for your post.
Are you only talking about Field frames in the Popover? Do you have field borders set to solid line? Dashed line? None (no line)? In the Layout Setup, what options do you have selected?
Is this behaving the same way in all layouts or just this one? If just this one, check the Layout Setup options as well as compare the field formatting in the Inspector.
Thanks! Deselecting the field frames checkbox in layout set up fixed it.