Confused - lighting circuit.

[Liam Regan]

Hello, any help will be appreciated. One of the RCDs tripped that protected the downstairs lights, kitchen and upstairs sockets. Process of elimination showed the issue to be with the downstairs lights. At the time it tripped the two kitchen lights had been on for sometime. Separate switches for them. I switched the hall light on and about 5 minutes later the circuit tripped.

I assumed it would be the hall light that was the issue. One switch two lights. I disconnected both ceiling roses. Went to switch the circuit back on and it tripped again.

I have had problems with the hall lights about two months ago that I thought I resolved. Why suddenly go now?

One by one I disconnected every ceiling light. The circuit still trips.

Am I missing an elephant in the room or is it time to call an expert.
Most of the ceiling roses have connectors as per image. Not like the ones i see in guide videos.

 

[Geoff1946]

Unfortunately random time RCD trips can be hard to diagnose. The fault doesn't even have to be on the same circuit, because adjacent circuits on the same RCD can interact depending on overall circuit loading.
Hence looking at the last item to be switched is no indication at all if it was several minutes ago.
It could be a faulty appliance on the ring circuit.
You probably need help.