Mule SX chirping
 

2017 Mule SX with 401cc engine. New in March, < 30 hrs on it. It has developed what sounds to me like a chirp only at higher rpms and under a load, like going up a hill at full throttle. It's not a bearing chirp as starts and stops with engine revs. Anyone familiar with this? Is it normal? I can find no leaks in the exhaust system. Thanks
Steve IA