G2S bed levelling probe

[ChrisP28]

Hi
I have built a G2S Pro printer and finally got it working.
I have a problem with the auto bed levelling probe. It has to be manually lowered and probe operates a micro-switch as it touches the bed.
My problem is that when the machine tries to probe the points along the right hand side of the bed, when seen from the control panel. The probe seems to jam in the guide and fails to trigger the switch. If the carriage is lifted the probe operates normally. Is this a problem others have encountered?
I'm working on a proximity switch alternative that won't need to be manually positioned or touch the bed. I just need to sort out a voltage divider to drop the 12V to 5V or possibly use a transistor to directly switch the 5V existing wiring.
Any thoughts would be appreciated.
ChrisP28