@matthewwritenburg - I'm on M1 and never had any issues up until 5.4. It's worth noting that all AU's still show up, including those from developers that have still to implement M1 native solutions so I'm not convinced that VST/VST3 plug-ins need to also be M1 native. However, if that is the case I would not have upgraded as many major developers still aren't M1 native (Native Instruments, iZotope, Toontrack, Arturia etc). Would also be quite annoyed that PreSonus didn't highlight that as a major issue in the patch notes.