It sounds like the issue with RGBplus not starting up with Windows 10 bootup might indeed be related to changes in Windows settings, possibly due to a recent Windows update. Your theory about user logins affecting it is plausible.
To resolve this, you can try the following steps:
Open the Task Scheduler.
Navigate to Task Scheduler Library > RGBplus (or the related task).
Right-click on it and select Properties.
In the General tab, ensure "Run with highest privileges" is checked.
In the Triggers tab, verify that the trigger is set to "At startup."
If the issue persists, you might want to reach out to New Version RGBplus support or forums for specific guidance on resolving this behavior. They may have insights or updates related to Windows compatibility.