I have this problem with at least 2 of my 4 S7 phones in my family.
When in a phone call that requires input using the keypad numbers do not enter. I have on occasion managed to use just 1 but I am unable to enter long numbers that are required when accessing conference calls.
Since this is happening on 2 phones I do not think it is isolated to just mine. My phone is 5 weeks old, the other one 5 months old.
I have searched online for a resolution but have not anythings relevant. Verizon troubleshooter did not help either.
Anyone know how to resolve this?