valve spring problem

I have my 318 out of my dart. Nothing special just painting her and doing all new seals and gaskets. I am trying to get my valve springs off. I have a generic lever style valve spring compresser. My problem is that when I compress the spring to get the retaining clip off. The retaining plate doesnt seem to want to slide down. Maybe I am just dumb lol. Havent had this problem before but this is also my first mopar. Something I am missing?