Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do what I can to provide the right answer to your question.
(I wish to comment, JustAnswer.com does not 'hijack' anyone. Such a complaint is unprecedented in my seven years of working with this website. We will of course respect your rights in every possible way.)
If your phone line is a digital line, faxes may not get sent. Many digital phone services do not support faxing. (Examples of digital phone services are MagicJack, Vonage, UVerse, Comcast phone, etc.)
Let me know more about your phone line service, the devices that are hooked up to it, and what exactly the model 922 is doing, and I will advise you further as appropriate.