Studio Display not working with MacBook. Help?

[GMac11]

My brother has acquired a Studio Display however has had no joy getting it to work with his M1 Pro mbp.

For reference (and to save time) the following has been proved:
* Display works with his iPad and his partner’s Intel mba
* His MPB works with other (non Apple) monitors
* When plugged in, his mbp charges but nothing shows in the OS indicating that a display has been connected
* Using supplied cable - however I imagine the cable must be ok as it works with the iPad and mba?
* All checks done for recent software/firmware updates

The only thing that my extensive googling has suggested is it could be the logic board - however if this was the case you’d think the display wouldn't work at all?

Both of us are at a loss at this point so any help would be greatly appreciated!

 

[HACO]

Is he permitting the accessory to be connected / act as a display? If not, it would only act as a charger.

 

[GMac11]

Is he permitting the accessory to be connected / act as a display? If not, it would only act as a charger.

I've read about that but does this appear on connecting the monitor or is there a setting you can delve into after the fact? He says there was no pop-up to that effect.

 

[demonix]

Has he checked the graphics/displays and thunderbolt/USB4 sections of system information to see if the studio display is listed, and if it is then something is not right because I'm certain that I never got any prompt when I connected a monitor to my mac mini M4 through one if its thunderbolt ports and it just worked (unless the studio display in question isn't compatible with apple silicon macs since it works with a intel mac)