Can't submit an issue on github

I wrote an issue full length and then i coulnt press “Send” because that button has been fade off.
Then I saw the orange guidelines of contributions box and clicked accept.
But i stil couln’t submit the issue. I reloaded via F5 and then the half of my issue has gone.
Whats wrong??

Not sure, but we haven’t changed anything (nor could we) with GitHub’s web interface. Are you sure you were logged into GitHub at the time?