I'm having the same issue and at this point I'm ready to fully switch to another DAW. It's pretty much impossible to tell which plugin because, at least in my case, they're all validated. So you'd have to go through them one at a time. Doing that is a huge pain, and even though I only have about a dozen I haven't been able to figure it out. The 3rd party developers don't always have the compatibility info readily available. One company I emailed responded and stated that Sonoma caused a lot of their plugins to stop working. I'm pretty much done with Logic.