I took two flights today, about 1 hour 1/4 each and same issue happened. Cruising altitude 9,000. I selected a descent at the final waypoint of about 3-4000 feet to avoid having to dive for runway. This last flight I did, the waypoint was CEA3 and I selected 6000 at that waypoint. I flew past the waypoint, and zero communication from ATC. I then asked for a lower altitude, with L key, no response. I then tried different keys to communicate with ATC, and no response to anything I tried. I finally decided to start descending to avoid over flying the airport at 9,000 feet, and was told to climb back to 9,000. I finally descended, switch manually to tower frequency at CYYC, and was given a landing clearance,
My question is, does PF3 not like when you change waypoint altitudes after loading flightplan? This has happened two flights in a row from different airports, both times changing to a lower altitude in flight plan .