Spend Money Window will not open

I have the same issue, spend money, receive money

I open bank register, make it full screen, then click 'split' and it will open a full screen spend money.

I get this a bit and have found making another window/screen full screen will allow me to open others.(But has to be full screen)

Also I have noted this happens more with two screens and moving myob from one screen to another.  Sometimes just closing myob and opening leaving on one screen helps.