Hi folks, I am opening this topic because actually I am not sure who to reach out (I already sent a message to process.audio asking for help and also asking here).
I am having exactly the same issue as presented in this old post.
Basically, I have a project in Cubase 15 Pro (mac OS X Tahoe 26.3) with 13 instances of the process.audio Sugar saturation open in different channels.
What happens is, if I do close Cubase and then reopen the project, it opens everything okay, the plugin instances are there, if I do click on them, they show up and when I do play the project they show audio signal passing by, but the actual process does not occur.
I need to turn them off and on (not the bypass, but the other thing like “steep” if I am not mistake that looks like you turn the plugin off and on) so they actually start to work properly. It’s been really tuff since if I do close Cubase I have to go through the 13 instances to resuscitate them.
Anyone has any idea on what can this be, or how should I troubleshoot an issue like that? I am a bit stuck! 
Thank you so much in advance for the attention!