What is WinGetActiveTitle returning instead of the expected window title?
It seems like either WinGetActiveTitle is not getting the title correctly, or it is getting the title from a different window to the one you are expecting. AHK's own Window Spy shows the title is as you expect, so the problem must be somewhere in the script or in AHK/WinGetActiveTitle itself.
See what AHK thinks is the active window class:
WinGetClass, class, A
MsgBox, The active window's class is "%class%".
We're not AHK experts though so these questions may be better answered on the AHK forum.