Looks more like someone scrolled down the screen and changed the Original Size and set whatever they changed it to as the default. So log in as admin, go into the fax option and check the Original Size is letter. Then save as default (bottom of the screen chooce Customize)
Attached is a sample of what is getting cut off. It appears like if it's zooming in.
Assuming it doesn't happen to scans and copies, please scan in a copy of the fax out and post it so we can see what you are saying.
When Faxing my documents appear scrunched like if they were jammed in transmission or cut off. Is there a setting that can fix this?