Solved DFU disconnected problem for Android 10 but results in increase in GATT Error

[Mxoh]

Hi there!

We faced the problem of not being able to perform Legacy DFU with Android 10 and newer iOS devices and have since applied the fix. However, since doing so we observed that there are more instances of GATT error. We have been monitoring DFU failures in our app and you can see a trend after applying the fix at around mid/end Aug, the DFU disconnected problem users decreased but GATT error users increased significantly. 

[Hung Bui]

Hi Mxoh, 

Could you let me now which exact fix you used regarding legacy DFU and Android 10 & iOS ?

Have you managed to reproduce the issue inhouse ? or you have only received the report from the customers ? If you can reproduce the issue I would suggest to capture a sniffer trace so we can have more understanding of the issue. 

[Mxoh]

Let me check with my developers and get back to you. I have been actively monitoring DFU problems faced by our customers as firmware update of their BT device is a key functionality of our iOS and Android app. I was surprised to see that GATT error shot up by so much since we fixed the legacy DFU highlighted here through the latest Android and iOS DFU library: https://devzone.nordicsemi.com/f/nordic-q-a/60658/not-able-to-perform-legacy-dfu-with-android-10-and-ios