New Window reduces current full screen (maxamized) window
whenever using a script to open a new windows the current window reduces its size from full-screen whenever the new window opens.
Full screen the current window
Click on a button that triggers a script to open a new window
New window opens on top of current window
current window exits full-screen (Maximize) and reduces down to previous size
Scale current window as large as possible so it does not get reduced when opening new window
Yep this is a well known and (understandibly) oft complained about window behavior on the Windows version of FileMaker.