The "main" reason for the Barrel is to "adapt" - not just provide an extension.
Hmm...Using this type of setup - can we even avoid using it in the first place?
Why?
Well, the short end of this story is - they "Fixed" the ferrites with a polyurethane "foam" once they achieved a given result.
When you put something like this, in line - like a coil/choke combo, one thing it WILL do, no matter what - unless it's soldered and bonded - is jiggle, move and screw up the initial tune it had - as it bounces around. Even crack - then things go from bad to worse...
These setups are no different.
These ferrite cores may be fixed in with adhesive foam now, but the box is plastic and bends - the screws provide no shielding.
That may have been why the barrel connectors loosened - the plastic construction does little in damping vibrations and will flex - so it can make joints like what you tried, fail.
I could go on, but, can you avoid using this or do you need something to fix a problem - we have to find you something better.
