I offline at 6 am. but my friend is telling my last seen is 3 hours ago at 10 am. It's showing me offline at 7 am. But the truth it must be last seen 4 hours ago. Why is wrong?
Probably you are logged in some other devices also. Sometime it shows because of Messenger app also. Just logged out from all the devices and uninstall Facebook Messenger and app.
It could be a time zone setting too. Check if you or your friend is set to a different time zone (correctly or incorrectly)