That would cause an instant trip at switch on
Bit hard to follow your postings and whether that is the case. Probably could be anything by the sounds of it.
Thinking back I remember a pub /restaurant where there was a massive junction box situation in the socket wiring
It was like Heathrow Airport on steroids
The owner used to direct me to it when an alteration needed doing
The older connecting and wiring drops weren't as convenient as they are now so the JBs were a necessary part of the work
I think what happened is their use contined after it was no longer necessary