'X-Powered-By', 'PrestaShop Webservice') Issue

[spydera]

I am using Printful.com as a vendor and suddenly the prestashop store stopped connecting to Printful on its own.

Contacted Printful and they replied:

Quote

We are expecting a header in the form: X-Powered-By: PrestaShop Webservice but we are receiving the header x-powered-by: PrestaShop Webservice   <-- notice lower case here

What's the reason suddenly this could be sending the header in lowercase?

In  \classes\webservice\WebServiceRequest.php   I have:

setHeaderParams('X-Powered-By', 'PrestaShop Webservice')

This is the only file where its being set as far as I can search.

Prestashop Version 1.7.6.5

Any help appreciated.

Thanks.