All files on box show locked by someone though it is locked by myself before editing. Hence unable to edit/upload the files on box.

I am the owner/ editor of my the file, locked my file, opened it at the desktop app and see the warning that it's read-only locked by another user?  I cannot edit file, clicked yellow ribbon at the top - got a message "file in Use, " , please see screenshot below. Could you please help to understand how the "lock" feature works ? Thanks