SET WINDOW RECT on Windows (10) - Different behaviour

Hi

Am I missing something with th use of SET WINDOW RECT under Windows 10 (v17R4)? It appears that the command is NOT adding the correct size to the height. Anyone else have this issue?

// Put this code into a script on a button in a form to trigger ON Clicked
// The form has a maximum height property of 7000 pixels

TRACE
GET WINDOW RECT($lf;$tf;$rf;$bf;Current form window)
// $bf = 280 The initial height of my window when it’s first displayed

SET WINDOW RECT($lf;$tf;$rf;$bf+1000;Current form window) // Add 1000 pixels to the height
GET WINDOW RECT($lf;$tf;$rf;$bf;Current form window)
// MacOS $bf = 1280 <- CORRECT, this is what is expected
// Windows 10 $bf = 1027

SET WINDOW RECT($lf;$tf;$rf;$bf+1000;Current form window) // Add 1000 pixels to the height
GET WINDOW RECT($lf;$tf;$rf;$bf;Current form window)
// MacOS $bf = 2280 <- CORRECT, this is what is expected
// Windows 10 $bf = 1027 <- NO change

Cheers
Allan