Most mfg's do not recommend putting a full glass storm door on a metal door. My suggestion is get rid of the full glass storm door and replacing the metal door.

Most metal clad doors still have a wood frame around the perimeter to mortise in hinges and striker for the lockset.The rest of the door is usually foam based and is why they consider them an insulated door. They can and do warp. It also could be an installation problem with either the hinge or lockset side of the jamb being set out of plumb.You can remove the door and sight down the lenghth of the door to see if it is warped, but check your jambs with your level to see if they are plumb.That's a lot of heat between your doors.You might consider a reflective coating for your storm door.They have diy reflective kits at most hardware stores. Generally people use them on their windows.