Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Sorry to hear you’re having trouble.
Yes, the printer would need to be on and in the ready state (auto answer) to pick up faxes without needing your intervention.
In that situation, it really won't work well with the answering machine. You'll need to either choose one or the other to leave on all the time, consider getting a dedicated fax line, or just receiving your faxes manually (when the line rings, press the START button to initiate the receipt of the fax).