I am seeing the same issue as was reported in this previous posting.
Continuing the discussion from Settings values disappeared in GUI:
I have found a workaround but thought I should report it as it might be a bug of help someone else. When I to open the GUI outside my LAN I do not see all the settings on the settings page. Additionally I cannot make changes to them when I click save. There is not error it just does not happen. If I am on the LAN and use the local IP address to access the GUI it works correctly just not outside. I do have port forwarding setup for port 8384 and I’m pretty sure it used to work in the past. My working around it to just use VPN and get directly on to my LAN and I then have access.