Recently for a month now i have been trying to do a Cork. I finally hit it but now I cant do it. What is different about the 2 corks other than me not landing it?

acually that is not a cork
its a backfull
cork is the same thing going from 1 leg and its easyer
i think you missed some frames in the second replay which made you lose your momentum or so.
if you have completed the spin you coul've landed it easly

Oh so maybe build up the momentum earlier so I can complete the spin? Oh and should I contract my legs instead of relaxing them?

yes try to build the momentum earlier.
idk if you are talking about the whole leg but contracting the right knee might help

Best i could do

mmh if you want somthing better try to do something to get momentum like backflip or backhandspring,
atleast thats what i did when i done my first back full which is below