After connecting my galaxy s7 ADB sees device ok for about 500 ms. In that short time logcat wrote out lots of text which immediately disappeared. After that it is marked as [OFFLINE]. I have tried restarting android studio, phone, USB debugging, ADB server and reinstalled SDK. I have allowed USB debugging authorization for PC.
PC OS: Win 10
Android: 7.0
Do you have any idea what to do about it ?
Change USB cable. Your current USB cable's data transfer speed is slow that's why it is detecting but showing OFFLINE.