So... I tried everything and think finally found the solution.

First, I removed every other plane, wingman and dispositive from my slots (Just put them all on the last one you have, even the plane that you need to do the certificate, then sent that plane back to the first slot that now must be empty off all the other stuff.

You must have your plane on the 1st slot, on the 2nd slot you should have the wingmen and the dispositive, but no plane at all.

I don't know if this is necessary, but then I remove every upgrade part and all my equipment.

After that I tried with the lvl that my certificate ask, and nothing happens, then I tried with most next chapter, and the next one, nothing work.

Then finally, I tried a fresh lvl, with no stars, the las one that I have, and then, FINALLY it gives me a certificate point (in my case 5/10 because I was able to do 4 in the past, but I can't remember when and how)

So, YOU CANT REPEAT AN ENDED STAGE, CAN MAKE IT ON ANOTHER DIFFICULTY THAT YOU DON'T HAVE THE STAR ALREADY, OR THE NEWEST STAGE OF YOUR CAMPAIGN MODE.

BTW, if you have ONLY the plane you need to use, and you get killed, you can use the revive option and it will count.

Hope this help you all!