I understand you to mean the sliding arms resist sliding into the larger recessed part of the arm. Pretty common. Solution is to remove the rubber boots, clean the rust and dirt from the arms then grease the arms and reinstall boots. Blue Ox offers a refurbish service for $30 at events where they do all that and replace any worn bits. Can cost extra for parts depending on what they replace. Or you can ship it to them.
Tell hubby BFH for sticking mechanisms is not the long term solution. ;)
I see there was a clarification while I composed this. I still stand by the previous paragraph. :)