Cannot connect to nRF52840 from iPhone/iPad running iOS 14 using nRF Connect App

[DDelforge]

Hi, 

As iOS developer, I'm facing a really strange issue : 

Using the nRF Connect app, I try to connect my BLE device, with success or not depending my iPhone/iPad configuration; you can see the detail below

• iPad mini 1 - iOS 12.4.5 
• iPad Air 3 - iOS 14 
• iPad Air 4 - iOS 14.2 
• iPad Pro 11 - iOS 14.2 
• iPhone 6s - iOS 14.2  
• iPhone 8 - iOS 13.3.1  
• iPhone 8 - iOS 14.3 
• iPhone 11 Pro - iOS 14.2 
  
  

All the devices which fails to connect (stuck in "connecting" state), are "Bluetooth 5.0 technology" according to Apple

Important thing to note, is that an iPhone 8 running on iOS 13 can succeed to connect. An iPhone 8 running on iOS 14 fails to connect.

These results are not random and produce the same output everytime.

To summarise, the problem seems linked only to iOS 14, but this is not true for all devices (It works perfectly fine on iPhone 6s and iPhone 11 Pro running iOS 14.2).

Could somebody guide me on why this is happening ?

Thanks for your input :)

[Susheel Nuguru]

Just to be clear, you are using nRF connect APP to connect to nRF BLE devices? So nRF Connect app has issues connecting to nRF on some IOS versions?

Maybe a sniffer log from one of the connection failure might help me undestand the problem a bit more in detail.

[DDelforge]

You are right : using nRF Connect App, I try to connect a nRF BLE Device (this BLE device is a nfr52840 in my case) using my iPhone.

Connection works well on android device (BLE 4 or BLE 5 Compatible devices)
Connection works as well on some iOS devices, but it seems, that some devices running iOS 14 cannot connect my BLE device. 

Regarding logs, unfortunately, I don't have much. it seems we are stuck at the step CentralManager.connect(), with failing device, we will never go further than this step.