Sorry, decided to start again from scratch. Time for a new design.
Thank you so much.
The setting you need to change is in Paypal.
Profile
Profile and Settings
Selling Tools
Shipping Calculations > Update
The check the box for
“Click here to allow transaction-based postage values to override the profile postage settings listed above (if profile settings are enabled).”
Many thanks fran4444, I would have never found it and wasted hours if not days.
🙂
I also note I found this FAQ eventually > https://docs.woocommerce.com/document/paypal-standard/#section-8
Excellent help docs woocommerce people. Sorry it took so long for me to find it.