We have a US account with 3 users. One of our users uses the ringcentral app on her android and one client is complaining that there is a lag in conversation transmittal (he'll say something and our user doesn't hear it for a few seconds). He is the only person who has said this, and when I call the user from my Polycom phone to her ringcentral cellphone app, there is no lag. Has anyone experienced this or know how to fix it, or if it's even a problem on our end?