I've posted about this before recentlyish, recent batches of banana plugs i've had from China have had very very loose spring bits, from multiple suppliers.
i ended up soldering the springy bits top and bottom, I hung them by the cross-hole on the soldering iron tip, heated, and flowed solder in as appropriate, you can do it pretty tidy. It's a PITA, but without doing so in my opinion they were near worthless.
The cross holes on some were also very bad and would need drilling, they went in my junk drawer.
I have not had such bad ones before.