Quizzes on CompTIA A+ 220-1102 throw 504's after 60s

Trying to access the quizzes in CompTIA A+ (220-1102) but 95% of the time when i click on their links, it will open a new tab, load for 60 seconds, then time out saying
The application did not respond in time.
In the network tab of dev tools it says 504 gateway timeout.