External Storage change - lose current shared links

Hi,
Got a bit of an issue.
We are currently running 16.04. Been using nextcloud for about 2 years now with no major issues.
All files are stored on a windows server share through the external storage app (Smb/cifs). Users share folders / files no problem.
I now have a problem, I need to move the external share to another windows server due to space.

When I change the connection host field from current server to new server (Duplicate setup), I lose all current shared links. If I change it back and apply I get all the shares back instantly.

Any ideas how can I change the server host without losing all my users shared links?

Evs