I have fed large amounts of Legacy Baryta and other similar papers varying sizes up to and including 17x22 into the top feed of the P5000 with no issues whatsoever. The important thing is to press the paper down firmly enough, and evenly from both sides, until you hear a click. If you hear that click the mechanism will grab the paper properly and feed it through. If you don't hear it, then you haven't fed it in firmly enough and will get the kind of issue you report.