Recently installed 82-265 is very stiff

My first suggestion is to remove the lock from the door and try to activate it using the thumb turn or a flat blade screw driver. See if it works easily with it off of the door. If it works fine, then it is an adjustment problem. You might need to adjust the roller on the door so that the door lines up "plumb" with the jamb. Or you could possibly need to raise or lower the keeper in the door Jamb. Lastly, there is a flat blade adjustment screw just above the top hook and below the bottom hook. You can turn that screw to make the locking hooks come out further or come in tighter. Try these out to see if you if can resolve the issue.