I find this tool useful for troubleshooting similar issues:
https://www.nirsoft.net/utils/opened_files_view.html
OpenedFilesView displays the list of all opened files on your system. For each opened file, additional information is displayed: handle value, read/write/delete access, file position, the process that opened the file, and more...
Optionally, you can also close one or more opened files, or close the process that opened these files.