MF644cdw multi-purpose tray does not feed paper when set on AUTO

[1775]

We have a new MF644cdw printer/scanner.  When we put a letter size piece of paper into the multi-purpose tray slot, it is pulled in, and print from a Windows computer that has the tray selection set to AUTO - the paper is not fed into the printer and the printer prints to a sheet of paper from the cassette tray.  We have assumed that if a paper is in the multi-purpose slot that the print source automatically sets the source to the multi-purpose tray slot.  Is this printer defective and does it need to be returned to the store it was purchased at a week ago.  It just does not seem correct if it is set to auto and the paper in the multi-purpose slot is not being printed on.  (Envelopes do not seem to have any problem. This paper is 20 pound printer paper.

[Hector]

Hello 1775,

The auto setting for the paper tray, will make the printer automatically pull paper from the tray based on the paper size registered. If you have letter sized paper registered in the multipurpose tray and legal size loaded in the cassette, the printer would pull from the multipurpose tray when you select letter and the cassette when you use legal. You can register your paper size using the steps in the link HERE.

[1775]

Both trays - cassette and multipurpose tray are registered as Ltr size paper. This is the size paper used most here. Other than an envelope, the multipurpose tray is fed letter size paper. It is pulled in -  and ignored - and prints from the cassette. The reason why we would put a piece of letter size paper in the multi-purpose tray - we have a page printed on one side and blank on the other and find a related single page that we want to put on the back of that paper.  We have been using printers for many, many years.  Always when we have put a piece of paper into the multi-purpose tray, no matter what is in the cassette - the printer prints on the paper put manually into the multi-purpose tray. What makes this printer so special that it does not do that???