Hi…,
Welcome to our new forum.
The stuttering when Simlink exits can be caused by the Simlink plugin being a different revision to the latest Simlink. Best in Simlink Plugin Settings to uninstall Simlink plugin from each FS, then completely uninstall Simlink using Windows uninstall.
If they exist delete directories
c:\Users\username\AppData\Roaming\Navigraph\Simlink and c:\Program Files\Navigraph\Simlink
Then download and install latest Simlink using the default prompted locations.
If still an issue, please posts a screenshot of Simlink Status page using Posting Guide - Uploading Screenshots
Cheers
Ian