Grid probe on the U axis

[Kulitorum]

On a IDEX machine, my probe is on head 1 - on the U axis. How do I make it prope the grid? - it is using the X axis, but the probe is on the U axis.

M557 U20:580 Y20:450 S55 Does not work, Error: No valid grid defined
M557 X20:580 Y20:450 S55 "works" but is using the wrong head.

Ideas?

Kulitorum

[dc42]

Does it work if you select the U axis tool with a T command first?