A fresh install is possibly necessary when the system partition has become too small since the last couple of releases.
#1 to do: make a full backups, use the built-in Backup/Restore tool in the Settings add-on.You can testdrive LibreELEC running on a USB stick and see if your Samba setup works to your liking.
I installed the latest generic version of LE on a USB stick. When booting from this on my Intel NUC, will it allow me to run LE from the stick without installing it ?
thanks