It is not uncommon in Clash of Code to have 100% on viewable tests while fail to get 100% in validators. I think this is unfair. As a workaround, I suggest to add a new button, which could be called “Presubmit”, “Submit Preview”, “Prevalidate” or in a similar way. It would run the code through validators and display the result without actually submitting.
Another option could be that if submit does not result in 100%, user is given an option to get back to his/her code and improve it.