Movie Extras - Pic/ThumbNail Not Showing

First of all, I want to apologize upfront if this is a simple fix and I missed it in the forums (so feel free to call me an Asshat AND attach the exact post where my problem was fixed, PLEASE.) I have had various issues with Plex since I first installed it (usual growing pains, it all works great now) and ALWAYS I was able to fix it by searching/researching the forums and following instructions. With this problem, I am not sure if my search is too broad/general because I have found a few articles that were related to my issue, but not the exact issue. I did try the various solutions and they did not work. So here goes ..

I have two Plex Servers, a Synology NAS 1515+ and an Intel NUC6i7 running Win10. (Real quick reason why I have two, I thought my NAS would suffice but it lacked the transcoding power, then when I got the WAF [Wife Acceptance Factor] - I bought the NUC.) Both Servers point to the same Library, obviously on the NAS. I have the folder naming structure as:

Music/
Videos/
          Home/
          TV Shows/
          Movie/
                 Movie Name (Year)/
                                Movie Name (Year).mkv   

In most instances of ripping my DVD Collection, I also ripped the DVD Extras. I followed the guidelines per the Plex Forums and the folder/naming structure for that is:

Videos/
   Home/ 
   TV Shows/    
    Movie/
           Movie Name (Year)/
                       Movie Name (year).mkv
                       Behind The Scenes[Folder]
                                         Some Description.mkv
                       Deleted Scenes [Folder]
                                           Gag Reel.mkv

I haven't had any issues with Plex recognizing the media, putting in the proper descriptions, playing the files, etc. NOTHING, across all of my devices and Apps, duh right? You follow the programmers instructions and **** tends to work properly.
However, give or take about a week half ago, I noticed that under the Win10 Server, no photos/images show up for the extras content. Plex recognizes it, plays it just fine, but it just shows a blank box outlined. The Synology Server though, PERFECT, no issues, displays the image for the movie extras, plays the file just fine, etc.

I have refreshed my entire library, deleted the trash, cleaned up the bundles, optimized the database, deep scan, deleted & added back a couple of the movies, edited the name of a movie extra to trigger an automatic update, I have done the famous "Plex Dance", everything short of completely deleting and re-adding the library.

If I access the Win10 Server across any of the Apps/Devices (iphone 6s, XBox One, Roku, iPad Air, WebPlayer, Plex Media Player, Win10 Plex App) the images are blank. BUT if I access it with the Synology Server, across all of the same Apps/Devices- perfectly fine.

Any advice/suggestions, or point me in the right direction to fix this would be appreciated. I know this is first world problems, and everything works GREAT - this really is just a PIA because everything else is so flawless and this drives me nuts.

Thank You in advance!