P/CAN is only to dump the presumed X and Z locations.
The control stores where it last knew that it was, and if it doesn't match when you HOME, it doesn't like it.
I'm really not sure the benefit if it dooing that in the firth place, but I wasn't consulted, so ...
And, just fer the records, NEVER hold anything else down during boot unless you know exactly what it is that you want to dump!
Again - I've never ran a machine like yours, nor doo I know your control board (HMI) so IDK exactly what all buttons that you have to play with.
But I doo have other Hardinge lathes with 18 controls, so ... I have enough info/experience to be dangerous at least.
Think Snow Eh!