My door handle fell on the floor one day, when I made a turn. Later, I went to put it back and couldn't find the retainer clip (horseshoe clip) and started freaking out -- WHER can you buy THOSE???
Well ... after calming down and making a further inspection, I discovered that my handles aren't original handles! They have an allen screw at the base! Wa-laa! A little tightening of the allen screw was all that was needed.
MAYBE yours are the same?