I am a new user to this program and I am still learning the ropes. After I have followed the instructions to climb to my cruise altitude the ATC tells me repeatedly (every 30 seconds) to maintain my cruise altitude. It never stops even if i acknowledge. Is this normal?

did you set your altimeter to 29.92 or 1013 as you crossed the transition atltitude? are you flying in the USA or outside? if in the USA, change the altimeter to 29.92 as you cross 18000/FL180jd