I also had no circle, just a red square.
The exam we provided is just a free sample for folks to play with - contact information is collected for paying customers (in a slightly different flow).
Not sure how you'll get back to me, it never asked for an email or anything.
The no-script might be at fault though. You might consider not using any CDN for scripts, only host locally.
I did not try again because I don't have a prescription (I submitted an image saying "no prescription"), and I realized it can't do anything for me (I just wanted a checkup basically - just tell me how I did on the various sized letter thing).