CEP Panel not loading in Animate 2024, M1 Mac Silicon, in both Rosetta and normal mode

I had a simple CEP extension for Animate CC 2022, which simply a html page that loaded another page from my dropbox in an iframe (an interface for running my jsfl scripts). Using an M1 Mac Silicon

Since updating to Animate 2024, the panel appears blank.
it does appear Window/Extensions, but even changing the index html to do nothing but trigger a test alert, doesn't load anything.

I have tried running Animate in Rosetta, and tried installing these test panels, which show in the menu, but they also don't load
https://github.com/Adobe-CEP/CEP-Resources/tree/master/CEP_12.x/Samples

Alternatively, the new UXP developer tools don't give me an option to select Animate as a Host Application, only Photoshop/XD and Indesign, so not sure what to try next.