Thank you a lot for the informations.
I tried with no stealthchop and the result is the same,
Motors are overheating when idle too.
Hold_current was the solution to keep them cold but it’s written to avoid it on klipper website so I’d better not use that.
I know the coils of these motors are pins 1-4 and 3-6 but I can’t find if they are wired correctly according to the btt pinout schematics.
But stepper z is wired the same way and it’s not overheating.
This is ridiculously unbelievable.