3DTOUCh works BLTOUCH does not

I have been using a 3Dtouch on my Tango(Rumba) converted CUBEX Duo for some time and its reliability got to me so I decided to upgrade to a Antclabs genuine BLTouch.
They are pin compatible so I expected it to work straight out. But it doesn't.
It self tests and lights red, no blue. It does not respond to any M280 commands and M43 S does not make it self test.
I plug my 3Dtouch back in and M43 does as expected.
Any ideas? or anywhere better to ask this question?

In case anyone is interested in the issue/solution.
I had servo0 defined as PWM2 but I had it plugged into PWM1. Ok so that would never work right? Only it did work albeit a little intermittently with the 3DTouch. How?
I had a wire to PWM2 in the same screened cable that I had cut off at the BLTouch end. Went nowhere.
The 3D touch must have been picking up the signal from the PWM2 wire.
Anyway, plugged it into PWM2 and works great. The 3DTouch would probably work a little less intermittently as well lol.