Hi,
Most likely the changes are happening in the db but some file system permissions changed and this prevents it from clearing the cache for site settings so the changes do not get reflected in the UI.
The /Data folder and all child files and folders must be writable by the web process user. The system writes cache dependency files under /Data/Sites/[SiteID]/systemfiles and it touches those files to clear the cache. If you delete those files it should clear the cache and if the folder permissions are correct those files should be re-created automatically.
I would check the mojoPortal log for related errors either from Administration > System Log or by downloading the /Data/currentlog.config file.
If you are not seeing anything logged recently in the log that is another sign that folder permissions must have changed.
Hope it helps,
Joe