G29 randomly deploys probe after measurement taken (3 replies)

Have you guys noticed a behavior in Marlin where G29 randomly drops the Bltouch probe just after taking a measurement?

I have recorded it here...
[photos.google.com]

I don't think it's a BLtouch issue, it looks more like a false deploy command is sent to the probe then retracted.

I have also observed this on G28 command.

Thanks
Ray