So when i input the awnser to Introduction to web applications - HTML Injection i do not get a server response and my the submit button does not do enything.
The awnser is correct im sure of it and with a incorrect awnser such as “d” i get a immediate “wrong awnser” with the normal red backround
This is the only place where i have such a problem
Edited for less messy reading 
I had something similar happen on a different module. I searched for another non-existent flag for like 40 minutes lol. Then I tried resubmitting the one I had and it accepted it.
I would copy the flag down/answer down, then try logging out and back into academy. I have noticed that the site will logout after a length of time, but never notify you. If you still haven’t got it, DM me what you are submitting so I can check it against my answer.
-onthesauce