I installed a door knob earlier in the year and thought everything went fine. Come winter, my house was not retaining heat. Found that the outside half of the door knob was not sitting tight to the door, though the inside was. This was letting air in around the knob, which I could feel with my hand from the inside with the door closed. Finally saw that there were two metal nubs on the outside of the housing for the mechanism that sits inside the casing of the knob were preventing it from sitting tight to the door.
Are these defects that need shaving off? Sanding it of course didn't reduce it enough. Is the hole for the knob not big enough? This is my first time running into this, and I didn't see anything in my Googling.
The door is standard 1-3/4 in. thick with 2-1/8 in. bore. Door knob is a Kwikset 991CN3SMTCPK4. See attached picture for gap and the nub I'm talking about that is impacting the metal door.