Cant initialize graphics in garage band - Imac late 2013 patched to sonoma (i7 and 780M graphics)

Getting this error in Sonoma on my 27" late 2013 imac with 780M graphics:

Unable to initialize graphics

Unable to initialize graphics. This typically happens when running inside of an unsupported virtual machine enviornment, or when running on an unsupported Mac.

I have "legacy metal graphics" right?

And I just set this up a few weeks ago, so aren't the patches built in to OpenCore? https://github.com/Dortania/OpenCore-Legacy-Patcher/issues/1008

afaik this should be working with this hardware. Do I need to do something to get it to work?