Post any workarounds you have success with here.
A work around that performs for me is to refresh the browser until the tests show up and the display functions. (Usually not more than 3 refreshes).
The tests will usually be marked as passing at this point, but you’ll need to run them again.
When that stops working (around 5 lessons), I close the browser window and open https://www.freecodecamp.com/ in a new window.
Another user found success with changing browsers.