When saving file it becomes unavailable for a few seconds

When saving a file via Dreamweaver cc 2017 directly to my test web server (network drive) it becomes unavailable for approximately 10 seconds. Using notepad ++ the file is available immediately. I disabled caching and notes (as I saw some people suggested) but it did not help. This is true in ff, chrome and ie. What can I do?

Thank you,

Shmuel