So I have had some luck thanks to the help team on Twitter.
so hue app worked but Siri and Apple home app wasn’t working.
so to be clear, I did do a hue bridge reset. I had deleted all home settings. Deleted the app and re downloaded.
i also installed a profile that deleted home settings (found via a Reddit but a Apple link - yes was worried about doing that)
after doing all that I wasn’t getting any luck.
Philips told me:
go to Apple home software.
click the button on the hue bridge
then add accessory and then click the bridge hue
enter code etc.
This worked. Previously when I went to Apple home app and add accessory it would already show the hue bridge and I would select it and would get the error message. I wasn’t hitting the button on the hue box.
to be honest. Not sure if all the other stuff I did before and 12hrs overnight helped before I tried this simple approach.
thought I would post as it may help others.