Product and version: FileMaker Pro Advanced 18.104.22.168
OS and version: macOS Sierra 10.12.6
Hardware: iMac 27-inch (2560 x 1440) and Acer monitor (1920 x 1080) with this arrangement
When a database window is open on the secondary monitor, the use of
Move/Resize Window [ Current Window ; Top : 0 ]
puts the top of the window outside of the current screen visible area (the top 150 points of the window will be cut out).
How to replicate: arrange screen as described (any arrangement where the top of the two screen is not aligned will do)