MagSafe charger and Apple Studio Display

Anyone else having this issue? I can’t charge my phone with a MagSafe charger using the any of the USB-C ports at the back of the Apple Studio Display monitor .

I can charge my iPad and a MagSafe Duo Charger using the usb-c ports but using a single MagSafe charger for my phone or MagSafe AirPods Pro doesn’t work. The MagSafe charger is fine as it works using a usb-c power brick plugged in to the wall but not if I use any of the USB-C ports at the back of the ASD. I can also charge my phone using a lightning cable from the studio display.

What is even more strange is that if I disconnect the thunderbolt cable from my MacBook, the MagSafe charger then works.

So in summary, all devices including phone, iPad, AirPods, MagSafe Duo will charge from the usb-c ports except for a solo MagSafe charger…..but it will work if I disconnect the Thunderbolt cable from my MacBook.

Firmware issue with the MagSafe charger perhaps? Or maybe a TB cable issue?