Hi Zhao,
I was using the Korg Microkey Arranger as the controller and the mi.1 Are you doing your test with the mi.1? See that was my orgignal quesiton if the Widi Bud works with other Bluetooth midi devices such as the mi.1 I found out that I don’t have to use cc#11 messages to cause severe latency or even hanging notes, just playing notes will do that. . The mi.1 works great with the iPad, and even when a PC receives midi from the mi.1 through the iPad. I am using Windows 10 Anniversary update and MS Surface Pro. Later, I will try on a differnt PC.