Additional things I tried that didn’t work:
- Opening it on my phone
- Opening it through a separate html file (following this guide )
- Borrowing a friend’s account
Thing that finally fixed it (for anyone stumbling on this thread in the future): deleting my progress (last resort step in the troubleshooting thread). Thankfully it was just my progress in this specific course, not for the whole certification.
I’m still puzzled about what was the issue, though.