for ringtone change always option was selected, how to change it to just once..

I am attaching screen shots for your reference..

Bro, in sounds and vibration>clicked on ringtone>selected sim> there is no + sign to add.. or to change ringtone.{go to settings>general management>click on reset>select reset settings..} This was already done, but there is no any change.But from ...

+ sign or ... is not showing in top right corner

hi bro thank you for your reply, but after "reset settings" also the problem is same. ( "unable set as ringtone" )