Thanks for reaching out to us here in the Community, @3H.
I'm here to help make sure that your issue about QuickBooks starts without being requested is taken care of.
First of all, I appreciate all the troubleshooting steps that you've done to get this working and for providing the complete details of your concern. I checked if there's an ongoing investigation about this, but there isn't currently one.
Since the issue still persists even after performing those steps, I highly suggest contacting our Phone Support team. They have tools such as screen-sharing (remote access) that can check your QuickBooks and further investigate why the software automatically launches itself.
You can check out this article for the detailed steps on how to reach them: Contact the QuickBooks Desktop Customer Support Team.
Please let me know how it goes after contacting them. I'm only a few clicks away should you have any follow-up questions or concerns. Take care and have a great rest of the week!
