ya I found that out on the kiox from here I think but I had the same issue with my HRM. found out you have to to turn on the Kiox first for it to connect every time.Nyon Bluetooth Connection Woes - Solved!
Over the past month, I've struggled mightily with the Nyon Bluetooth connection to my phone. The Nyon connects to my heart rate monitor flawlessly, but would often fail to connect to my phone, or randomly (so it seemed) disconnect. I went through the process of forgetting the devices on both my phone and the Nyon over and over, reconnecting, failing, disconnecting, restarting ... oh woe is me. I felt like one of those crazy people who keeps doing the same thing over and over despite it not working!
I even called Bosch twice about the issue. They answer the phone and are very responsive, but not terribly familiar with the product as it is so new in this country. They absolutely get an A for effort. Anyhow, as it turns out, the Nyon will only connect and stay connected to the phone when the Bosch eBike Connect app is opened. So there you have it! Why it took me so long to figure that out, is a mystery. I will say that it is not mentioned in the manual, and neither of the Bosch techs I spoke to was aware of that requirement. But now it works, and we're all happy. I will update the Bosch tech support with this information.