after 2 days of furstrating reasearch across the net trying to understand the base of the problem i have finaly came a cross to the solution that solved my clock drifts . the solution for that is to cheack\uncheack “use system timestamp” inside Cubase under: studio > midi port setup , bellow the midi port table cheack or uncheack (depands on your system just leave the 1 that overcome the drifts and the clock stays on time)