First one happened with me before and obviously it is not fixed yes..

When I try to hack a solution nothing loads in the hacking page.

Second one is when I submit a solution this happens..

First maybe the solution is "In queue"

then "Running on pretest X"

then "Wrong answer on pretest X"

AGAIN it is displayed "Running on pretest X"

finally "Wrong answer on pretest X"

If it does run again on CF server it would be a drawback on performance.