Plex keeps scanning my media yesterday after I’ve added a few new Movies to my Movies library.
I’m using Synology DS1815+ as my server and the Library is in my Synology as well.
There are no changes in the directory. I’m the only user in the NAS.
I’ve uninstall and reinstalled PMS but it does not solve anything.
Attached are the logs.
Hope to hear from you soon! 
The Plex Media Server logs are more helpful as it indicates why Plex decides a rescan is needed.
A possible reason: I’ve seen this behavior before when a Mac is connected to the server via AFP (it may do it on SMB as well). Occasionally Finder goes nuts and continually writes to a hidden file on the share even when you aren’t doing anything with it. Disconnecting and then reconnecting the share would stop the rescans.
@gbooker02 my mac isn’t connected to the server. Both my plex and the library is in my synology. My mac only view plex thru web plex.