I am currently using a beta version (which was in the most recent update and allows for pinned messages). Using the 3 lines in the upper left (to the left of 'Conversations'), I used the Customize feature to change my notifications sound to the one I prefer and turn off the vibrate feature.
However in each individual conversation, if I click on the 3 vertical dots to the upper right and select Customize, it shows the default 'beep' as my notification sound and the vibrate feature is on... for EVERY.SINGLE.CONVERSATION.
I have to go into each one to change this.
Is this just in the beta version?? If so - I'm switching back!
I understand how important it is to be able to customize your notifications. Just be make sure I understand, are you saying that it will not allow you to customize the notification for each contact? Since you are using the Beta version, it may be working as designed.