Hi tbskoglund. Thanks for the message today. I successfully updated to GarageBand 10.4.6 and confirmed that it was running natively (not through Rosetta). I then upgraded my MacBook Air M1 from Big Sur to Monterey and can confirm that the Eventide H9 Plugins are still visible in GarageBand. The only thing I noticed is that upon launching GarageBand, I was prompted to lower my security settings to allow the plugins to work. Once I allowed that, GarageBand opened up and everything was perfect. Thanks again for your help and prompt responses!