@slash1andy I presume its caused by the PayPal Plugin as the issue isn’t happening on 2.0.0
The Siteground Optimizer Plugin hasn’t changed or updated at all so everything is the same there.
It only started happening on the PayPal Plugin 2.0.1 which the change log shows it is for a fix for showing the PayPal button but that update may have fixed it for some people but now must have broken it for others
2.0.1 – 2020-05-26
Fix – PayPal buttons not loading on the page, accompanied with the javascript/console error: “paypal.getFundingSources (or paypal.Buttons) is not a function”. PR#740
Thank you for the information on the debit/credit card bit!
Let me know if you find a fix for the PayPal button as I will stay on version 2.0.0 for now as everything is working good.