PayPal Extras Mastercard/Synchrony login problem

Description

I have been trying to view the account details on my PayPal Extras Mastercard and pay my bill online. However, every time it forwards me to the Synchrony Bank site, I get an error message saying « Login not permitted. We’re sorry. We have a problem with your account that needs to be fixed before we can restore your online access. Please call us at  »

I have tried calling Customer Service multiple times and they have never fixed the issue. The only customer service agent who ever even offered any kind of solution was one who said that certain web browsers won’t work. But I have tried Chrome, Safari, Edge, and IE and still get the error message with all of them. If none of those browsers work, then what browser does?

Has anybody else had this problem and maybe been more successful at getting a solution? It really makes me want to cancel my Mastercard since I am not able to view my statements or do anything else with my card online.