--- preferencesmanager.py
+++ preferencesmanager.py
@@ -231,7 +231,7 @@
         self.core.apply_session_settings(
             {
                 'listen_system_port_fallback': self.config['listen_use_sys_port'],
-                'listen_interfaces': ''.join(interfaces),
+                'listen_interfaces': ','.join(interfaces),
             }
         )

Interesting issue, you can corrupt the settings file by having symbols in your Socks5 Auth password.

*v6]>eP#}K!#a@C=!t|Y}w4yLbls"4+4
This was the password I was using and whenever I setup my Socks5 the settings would revert on restart.

I have tested with a shorter password with symbols and that works, so I am guessing it is either the length of the password or specific symbols.

linux ubuntu 19.10 when calling the ui from the tray icon the ui crashes. starting deluge from command line returns errors. log file attached.