Problem with N1 in 0 in Wilco Airbus

When I climb to cruise altitude my engine N1 display acts weirdly and decreases very slowly. It slowly decreases until it reaches 0.0% then then engines themselves lose power and the only way to regain power is to descend to a lower altitude. When I have clear skies (default weather) it works perfect with no problems but when I select ASA I have noticed changes the SAT or TAT Temperature.I think ASA that was causing the problem by the weather not loading correctly and giving false information which the airbus computers followed and was causing the engines to be starved of air.Pls Help me!!!!