Huge apologies to Yuasa and Amazon. It turns out my NOCO smart charger was on the blink NOT the battery!
I thought I’d top up the charge on my new replacement Yuasa battery and it wouldn’t take the charge even though it measured 12.8V plus with my meter. Tried a CTEK smart charger and all became clear, the NOCO was to blame not the battery!
Oh well, I have a great new battery and a spare too 