We found that, an android phone(Android 5.1) can not update device version by DFU,and then an android phone(Android 8.0) can do it.
The two phones used the same APP version.but we found some page that they have diffent content.
Please update the case with more information. What exactly doesn't work ? If you couldn't do DFU update, what exactly happened ? Which firmware did you use to update ? Which SDK ? Have you made sure the app on the phone updated to latest version ?