An update: This morning the lights now work 🎉
Every light switch is responded to immediately. No having to press multiple times to get it to work.
So it seems to be NodeJS as I had 12 installed and zigbee2mqtt needed 14 as a minimum, so put 16-LTS on to the controller and that seems to have finally fixed it.
Even the living room light which did a funky blink when it turned on now turns on smoothly
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