Not saving settings

Can anyone think why my server seems to forgot some settings?
Like i setup so i dont need to PIN code login and yet 24hrs later i am asked to login and check settings and the setting has changed back?
And i usually set movies to show 3 trailers before a movie (quite like seeing trailers), but often sit down to put a movie on and get no trailers, go upstairs to check server settings and its gone back to 0 in setting?

Bemused /cry

Because you let your web browser erase cookies and similar session data when you close it.

Do keep in mind that these settings are not for the server in general, but only for the particular web browser with which you are settings them.
This is true for all settings under ‘Web’.
If you are using other Plex clients, you have to make these settings in their preferences.