Yes, I would say cook the filling before putting it in the ravoli. Also, add some beaten egg to it. I would fold the ravoli in half to close it, rather than sticking two sides together.
I would use egg to stick the ravoli together.
Also, I would be careful, when lowering them into the water. Maybe put them in a frying basket, brushed with oil and use this to gently lower the ravoli into the water.