What theme are you currently using with your site? I had the same issue with the "Save changes" button and it ended up being a bug with Edwiser RemUI. The problem is resolved in version 3.5.2 of the theme.
In reply to Jeff O'Fallon
Re: Upgrade from 3.3.4 to 3.5.1 - Admin settings not saving
by Sarang Nair -
The issue was a small coding error and has been fixed after we released a hotfix for Edwiser RemUI theme.
@ Patrick, Are you still facing the issue? Also, are you using Edwiser RemUI theme?
@ Patrick, Are you still facing the issue? Also, are you using Edwiser RemUI theme?