Since this is your first post, I will go along, but I am questioning where you have a AR-15 at all!!!!!!!
Unless this is a 9mm rifle, you have a real problem. One the 5.56 AR-15 rifles, the cocking handle has a hole on the end that grabs the carrier key. The gas tube runs threw the hole(like a guide) then the key goes into the hole, with the gas tube on the inside of it.
With the key/tube inside the handle end hole, there is not way that the cocking handle is failing to grab the key/carrier.
Pull your handle back, pull the carrier/bolt out, then pull the handle all the way back. At the end of the rearward stroke, push the complete cocking handle down to have it glide down out of the retaining slot and pull the cocking handle. Unless you have the wrong cocking handle, or the end of yours is broken, You have been dreaming again.
Know if you saying that the carrier is coming back, but is leaving the bolt in the barrel extension, then you have installed the bolt/carrier wrong, or your cam is broken and is not rotating the bolt out of battery.
As for your light hits, break the bolt down and check the firing pin channel. Chances are that it is full of fouling and needs to be cleaned. The use of a Q-tip from the back end and CLP will do the trick.
Here is the repair manual:
old.ar15.com/books/TM9-1005-319-23.pdfAnd since you have been stumped by the simple cocking idea, the user manual;
old.ar15.com/books/TM9-1005-319-10.pdfP.S. Welcome to AR-15.com.