I posted a thread about my issue on the Dorico forums: Long-standing issue with "Screaming Rock Organ" vibrato in HALion Sonic
In short, I created a preset of the Screaming Rock Organ sample that enables vibrato by default, but I’ve dealt with an issue for the past few years where the preset’s vibrato is disabled when I reopen a project in Dorico, even though the Vibrato Bypass dial indicates it’s enabled.
The way I’ve worked around this is turning Vibrato Bypass to the right then back to the left; I thought I would be able to reproduce this bug consistently by reopening my current project, however it only happened intermittently.
I was able to reproduce it consistently by reloading the sample while Dorico was open: https://www.youtube.com/watch?v=cr9nEhbEb48
Thank you for reading!