For those dealing with this particular issue, the solution consists in locating the VM Server (where the plug-in has been installed) and simply re-start the service (SnapCenter Plug-In for SQL Server).
If the service won't restart, you have the option of removing it by uninstalling it and re-installing it again.
Please note that if you were to remove the plug-in from the SnapCenter Center, you'll be deleting all previous backups associated with that VM. That might not be a good idea!! The best solution would be to uninstall it on the VM side and then re-install it (if needed).