When pressing the “Submit and go to next challenge” button, it seems like the page is not loading, and often takes a very long time to show the next exercise. Sometimes a page refresh is required to force the exercise to progress to the next page. This seems to happen on all of my devices (3 different laptops) on wired, wifi and mobile data. Have got the same issue across Chrome, Firefox and Edge.
Oh okay. I guess you can try to disable any specific extensions in your browsers that might interfere with running the FC C test. Additionally, here is a link to an article explaining a solution to similar challenge you are facing Passed the test but now the next lesson won’t load