IS THERE A LIMIT TO HOW MANY STUDENTS YOU CAN HAVE IN A CLASS? I'VE GIVEN ALL MY STUDENTS THE ONE CLASS CODE BUT ONLY SEE 14STUDENTS.
I'm not aware of there being any limit, but it would certainly not be fourteen. You say you've given the code to all students, but have they all used it? Duolingo for Schools has been experiencing some delays with assignments; you may be experiencing a similar delay with your students showing up.
I have a couple of "archived" classes where I move my students when they graduate. Call me a hoarder, but I can't bear to delete my beloved students. Also, I like getting reports that they are still learning the language. :) My largest has 450, and room for more.
I think Atervanda is right, either your students haven't actually linked to your class yet, or there is some weird delay in them showing up.
Tell your missing students to click on the blue silhouette in the upper right corner
scroll down to "settings"
click on "progress sharing"
and input your classroom code.
This should instantly solve the problem.