Used the sandbox many times, stopped working on the project about a month ago, now that I'm testing using the eBay API again I'm finding that the sandbox site is completely broken for me. I can get to the main page after login, but any attempt to navigate to any other page results in it returning me to the main page instead.
I am able to log in to my testuser_ account fine. When trying to go to my 'selling' page to check if my selling API calls correctly scheduled listings, it simply refuses to navigate to the selling page.
Any ideas? How can I resolve this and what can I do to prevent it recurring in the future?
07/05/2021: Still seeking resolution of this issue. The main page now does not completely load, in addition to the aforementioned problems.