I never seen such compatibility issue between RCA connectors before!
Yesterday I soldered KLEI Pure Harmony RCA connectors to my DIY Duelund DCA16GA cable.
When I connected these RCA to my Chord Qutest DAC, I damaged Qutest female RCA connector central pin contact.
After that, I opened Qutest and see contact plate was moved from its place.
I returned contact plate to it’s place.
Now my Qutest works again! But I can’t use KLEI RCA connectors with it.
On other hand I can use cable with KLEI RCA connectors between my phonostage and amplifier. Both use Vampire female RCA connectors.