I don't know if you damaged anything in the probe circuit or on the Duet with the 5V output. The Duet2 Maestro can handle the 5V (up to 30V).
You can use two resistor in series to get the value close enough. You can use a 220 ohm with a 20 ohm in series. You can also use two 470 resistors in parallel (value will be 235 ohms, but close enough). If you are good with soldering SMT parts, the two 470 resistors is easier to solder on the output pin to ground. I used 0402 sized resistors, but you can use the larger 0603 size also.
Make sure you have 1.21 version and later since you are using P9 mode. If you are using an older version, change it to P5.
Does it give you any error when you send the commands? Check the console for any messages. Are you sending the commands with a macro? When you send the commands, does the probe blink?
If you have a servo motor, you can also use that to check if the wiring is correct. I found out my servo did not deploy and so the error was somewhere with my config and software and not the hardware.
Lots of detail and info here:
https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe