Philips fidelio headphone does not connect

I have a Philips fidelio l3 headphone which connects to my apple 8 but not to my more recent Apple TV 4K or an apple 13. Nor does it connect to my old iPad. When opening the Bluetooth connection it just fails to appear on the devices list. It’s a quite recent headphone and sort of high end so you don’t expect it not to not connect to an apple product. I posted this question at Philips but they just refer to apple. Anyone got any ideas about causes or solutions?