It is the new page. I just tried again and it is still working. I’ve made ~6 successful payments today.
I was in touch with PayPal tech and they believe the problem is on the PayPal side. By the time I got to the final tech supprot person earlier today, the guest option problem appeared resolved. I have been testing it throughout the day and so far so good.
I am experiencing the same problem and have not found a solution. I have contacted PayPal and will post back here if I find anything out.
