phone not ringing on incoming calls since update.

[fullpampers]

Fongo mobile version 3.9.4.13

Iphone 5s under IOS 10.1.1

Since I updated the app, i can now answer calls from the lock screen (which is nice). But my ring tone keeps setting back to "sonnerie systeme" my phone is in french so I'm guessing it's something along the lines of "system ring tone" or something like that. and there is no sound.

I keep resetting it to my chosen ring tone, but it keeps setting itself back to "sonnerie systeme" and I am missing calls because the phone doesn't make ant sound on incoming calls.

Thanks for any help/fixes

J-S