Remove incoming call view on destroy method call
MODIFY
MatrixKit/Controllers/MXKCallViewController.m
MatrixKit/Controllers/MXKCallViewController.m
@@ -231,6 +231,8 @@ NSString *const kMXKCallViewControllerBackToAppNotification = @"kMXKCallViewCont
[hideOverlayTimer invalidate];
[updateStatusTimer invalidate];
+ _incomingCallView = nil;
+
[super destroy];
}

Remove incoming call view on destroy method call