Thanks for your reply Terry.
Since your reply, I've been having a closer look at the difference between the two computer setups.... I've worked out that getting my new computer coincided with version 2019.116 with the new auto driver colour management settings feature in the printer profile - so old computer on v2019.115 - new computer on v2019.116 and above.
I've then worked out that for years I've had the Colour Mode in the printer driver settings set to 'Colour' and not 'No Colour Correction' which turns off all the printers colour correction.
But as I make my own ICC profiles it hasn't mattered as the profiles just make the colours right..... as long as I keep the Colour Mode in the driver set to 'Colour'
Of course, this went all wrong when the auto driver colour management settings was ticked 'on' as it then - quite rightly - turned the Colour Mode to 'No Colour Correction' without me noticing and to be honest I didn't even know what it did!!! (i do now
)
So I set it back to my old but 'wrong' settings and it now seems to be printing nicely.
I think I now need to re-profile all my papers with the correct settings just to keep everything neat and tidy
Your reply has been most helpful as it made me re-look at the driver settings - many thanks