What you hear is perfectly normal. I have had my iExos100 for over 11/2 years and have used it with ExploreStars/iPad and a Fire HD8 tablets, and now use it with a serial cable connected to an ASIair. I have had no issues and my operations and tracking are still excellent. Better with serial.
Vero Beach, FL
Mounts: ES iExos 100-PMC Eight
Scopes: ES ED80CF, ES AR102, Meade ETX 90 EC (Deforked)
Software: ASIair Pro, iPad Pro, MacOS, Starry Sky Stacker, Affinity Photo, Lightroom, SkySafari Plus
Cameras: Nikon D600, D5500
Misc: ES USB Power Bank, Rigel QuikFinder, 0.8x Focal Reducer
Filters: Optolong L-Pro, L-eNhance