I have seen this occur with many different programs though I admit that I have never had this occur using ActivePresenter.
The window is basically being placed where it last remembers being.
While not effective in every situation, I have been successful at times using a
SHIFT + Right Click while hovering over the tab associated with the window followed by the Move option that appears in the pop-up window.
After selecting Move - you should be able to either move the window over from the other monitor by nudging with the arrow keys or by trying to click and drag it over from the edge of the screen.
It can be tricky to get it and I have had to try several times before finding success or finally giving up but it may be worth a shot.