I just took off from KLAX and am cruising at FL370, heading north. The throttle was set at 63%, but it quickly went down to 52% and then all the way up to 100%. It stayed like that for 30 seconds before going back to 63%. It just went up to 86% and back down to 75%. Now, it’s back up to 81%. As far as I could tell, there was no change in wind. What do you think happened?