Plug the USB cable from the monitor directly into your Mac Studio. Do not use any hub.I got Studio M1 Max today and the effect is exactly the same as on my MacBook - ACD 30" works ACD 23" does not. Tomorrow I expect to receive the adapter from BENFEI
Mac Studio and old Cinema Displays
I hooked up my 23” using this DVI-to-USBC adapter. Easy peasy. https://www.amazon.com/gp/product/B0768RFQ83/ref=ppx_yo_dt_b_asin_title_o03_s01forums.macrumors.com
and if it does not work I will try Club 3D.
A big disappointment is that the ACD 30" does not always wake up from sleep. Has anyone had this problem? Maybe an active USB hub is the solution? I suspect it's a matter of that extra USB power supply....
Doing so may also reduce the chance of brightness control issues from the keyboard.