I don't know if I'm explaining this correctly, and I'm sure it's just a setting that has been overlooked, but here is my problem. I have a grandstream gateway with aastra 6753i phones running latest of 3CX. When I call a user that has an auto attendant, I hear the button press on my handset, but their auto attendant doesn't register the tone. Where do I look and what do I have to do to configure the system to properly register these tones? Thank you in advance.