selectPDF issue - fields going to defaults before export

On my page i have a dropdown that allows the user to select a number and a date picker so they can select a date.

The number they select triggers groups to display the corresponding number of rows with dates above the input fields.

When i run my selectPDF workflow i get a PDF but all fields have been reset to their default values.

Where am i going wrong?

I managed to work around this by setting temp_text (and a load) of other values to auto-bind to the changes i made. I still cant work out how to stop the checkbox from resetting!

Is anyone able to help with this?