I am experiencing the same problem. I cannot enter my card details in the provided space. To resolve this I tried using a VPN. That did not work. I changed my country location in my account. That did not work. However, upon following your advice, about using a different browser, it now appears to be working.
When it was not working, I was busy using Google Chrome. Once I switched to Microsoft Edge it allowed me to enter my details.
Just thought that I would share, since I also experienced the same issue.