Hi, I'm Robert and I'll be helping you with your printer question.
It should work especially from the multi feed
Have you set the paper size correctly on both the printer and the computer you are printing from?
Also remember that 8.5 x 14 is very different than 14 x 8.5.
You might try reversing that or a few printers expect you to feed that sideways
I would love to give you better and I don't get anything unless you are happy and give me a good rating
But unless the printer is broken it should work on legal paper and these situations are almost always caused by a bad setting.
If you would like I can log in remotely and fix it for you that way