MBP M1 Pro usb accessories disabled prompt when connecting a display using USB-C

I have the MacBook Pro (14-inch, 2021) with M1 Pro and connecting it to the ProArt Display PA329CV. When I'm normally working on my laptop the display works fine. However if the Mac goes to sleep and then I wake it up, I see a notification saying "usb accessories disabled". The odd thing is that the display still works with the MBP, and the battery indicator says fully charged and connected to the power adaptor. I'm confused as to what the issue is, or whether it's a bug with Mac OS. The ProArt Display PA329CV can connect to the Mac via USB-C with 90W Power Delivery. If I try to use the USB-C connector simply for the display, and use the mag-safe charger to power the MBP then the monitor doesn't work at all. Does anyone have any suggestions?