Can't Add Shipping Charges

Shipping method set up as UPS realtime, to use negotiated rates. I am getting the correct rates, but I need to add a 5% surcharge. However this is not a selectable option, any idea why or how I can work around this?

This is default behaviour in the latest versions. Hover over last line of each section and you will see inout fields to add new rates

Ohhhhh, thanks.

It is very odd that there are values there you can't check, change or delete. I wonder why those are there? It would be a lot less confusing if the charges remained checked once added and saved.

Looks like many customers had issues with setting free shipping. So they hardcoded this line