>Is this likely to be a configuration issue at my end
No.

In fact it was quite a deliberate decision to completely disable the whole shipping address input when being redirected to paypal as – in my opinion – it only confuses the issue of paying for an order.

That being said, there is also a filter available in the plugin/gateway that allows to to override this behaviour as it suits your needs (i assume here you know what wordpress actions/filter are and how they work).

As a starting point you could do this sort of thing
you should be able to adjust things from here as you need them to be in your particular circumstances
see
https://developer.paypal.com/docs/classic/paypal-payments-standard/integration-guide/Appx-websitestandard-htmlvariables/#paypal-checkout-page-variables
for parameters paypal accepts

add_filter('wppizza_filter_paypal_parameters', 'myprefix_paypalfilter', 10, 2);
function myprefix_paypalfilter($parameters, $order_formatted){
/* will revert the value to the default of 0 */
unset($parameters['no_shipping']);
/* alternatively override to the value you want there like so  */
$parameters['no_shipping'] = 0 ; /* 0. Prompt for an address, but do not require one */
/*
setting some default values according to your settings, using the values returned in $order_formatted.
do a print_r/vardump $order_formatted to see all order parameters . It should be obvious what is what
*/
$parameters['last_name'] = $order_formatted['customer']['cname']['value'];
$parameters['address1'] = $order_formatted['customer']['caddress']['value'];
$parameters['email'] = $order_formatted['customer']['cemail']['value'];
/* and so on */
return 	$parameters;
}

Hope that helps