Hello, when you open and close the tray what settings does it show on the screen? Or when you print a config page what does the trays come up as? I would check the tray guides, and the paper handling settings, if the guides are not set properly it will cause it to jam, not pick up from the selected tray, will switch to another try. These machines, as well as, the 4540s have that same issue, even if the guides look flush with the paper, they might not be, I would start there and to make sure.
Hope this helps.....