We use both the iOS and Android DFU library to support DFU through our mobile application. Recently we found that Samsung phones running on Android 10 have a problem with DFU both on our app and when using the NFR Toolbox. Strangely it shows DFU disconnected on our app but Gatt error in the NFR Toolbox.
We never had a problem with DFU on iOS before. And after various rounds of testing with different with Android devices we finally narrowed it down to Samsung + Android 10 to cause this DFU failure. On other Android devices that run Android 10 for example Huawei and Xiaomi does not encounter any DFU problems. And Samsung phones on other Android versions do not encounter this DFU problem too. We even had a Samsung phone that was originally running Android 9 and it worked for DFU but after upgrading this same device to Android 10, DFU stopped working.
I wonder if this is a known issue as more and more Samsung devices on Android 10? And any suggestions on how to troubleshoot and fix?