I experienced am similar phenomenon. I disassembled the rear end and while i was there i rebuilt the handbrake calipers.

I didn't adjust the cable at the handle end and when I put it back together I found the cable was now too short to connect up to the calipers.

My solution was to pull the cable and sheath rapidly in and out of the body void and after a couple of minutes it suddenly became the right length.

My interpretation was that the sheath wasn't bedded properly in a hidden internal ferrule which effectively lengthened the sheath and shortened the cable.

This may not be the case but it worked for me!

 

I got it I think,it does make ratchet sound when assembled complete on rotor,I wish there was a basic adjustment before going back on,I thought it was loose off rotor then I couldnt hook cable up so had to loosen up more,I hope its not too tight on rotor,kinda hard to tell now that its all in the cage up in the car,Dropping the rear is not a bad job at all,just little stuff like this takes so long because there is nothing out there on how to do the little stuff