I have to push the "end call" or "answer" button multiple times in order to answer or disconnect from a call

[Lucyfur22]

Whenever I receive a call, I push "answer" and it just stays there.  It stops ringing, but doesn't complete the answering process.  I push again, and it may or may not connect.  Usually a third time and it will connect.  Same when I hang up.  I usually just have to wait for the other person to disconnect.