While training on our new scopes using AP GTO CP4 mounts with the iPad screen in Daytime Mode NOT in Night Mode red, we've had a couple of occasions (after a GOTO is performed) while using the slewing buttons to center the object in the FOV, the slew control buttons become non-responsive and the little scope popup that shows the 4 selectable slew speeds turns red.
The only way out is to disconnect and reconnect and sometimes shut down SkySafari and restart it to regain use of the slew controls.
Because I can't keep track of any sequence of button pushes while operators are doing their thing, I have no idea why this function freezes up. Maybe simultaneous button pushes contrary to each other? Holding down one of the buttons too long? Changing the slew speed while slewing?