This can only happen if you clicked something on the page where you edit the promotion history. Like if you accidentally uncheck the "I started training" box and overlook the warning box, it will reset you back to white belt.

Just activate all the belts again one at a time, they should have the same data as before.

I did but i lost all the votes!!

You would that anyway when adding the first degree (unless you go by time served auto promotion)