@Phaedrux, @PaulHew , I think I have found out what the issue is or issues! The first was the sensor height after it was moved further up, the nozzle will now home correctly and the correct distance to the bed!
The other issue which I’m sure contributed to both the z cal and my board locking up was I’m sorry to say bad workmanship, after we spoke Paul I started shift stuff around for the standalone, thats when I saw the Z axis driver plug pins where not sitting in line it’s plugged it fine when you pull the plug they are all aligned, all have continuity with no shorts but some solder got further into the pin causing a poor connection!
I’ve now redone the plug and so far so good, I’ve Carried out G32 and will attempt a print shortly to see if there is any difference.
Either way I can’t thank you both enough for your help, feel like I might actually now get somewhere!
I’ll update the thread post print!