If you make edits to your game settings. Ini file and the server host does not like them when you save the changes, the server name becomes changed and the settings are reverted to default settings this may be your problem.
U need to select unofficial pc servers in the "join ark" then weather its pvp/pve or not and if u passworded it tick the password box then search the name of ur server. Also have the favourites box ticked add it to ur faves and then everytime u click join ark ur fave will be at top