A simple replacement, all cable as should be, two loop neutrals and fitting neutral in one block, loop in, loop out and live to switch in other block and switch live and fitting live in last block, mcb back on, light won't switch off.
Am I being stupid?
You do seem to have got everything correct. One would expect that the switch is faulty or you haven't done exactly as you report. If the light is full brilliance then look at switch or center terminal block for fault. If not full brilliance look at if switch and neutral wire swapped. The latter is also likely to make some other lamp come on dim as well. Be careful as lights are not normally through RCD and contact with live wires hurts and can be fatal.
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