@Samh321 I have the exact same problem.   I have a SSD attached to my Archer C2300 router via USB, that I've shared.   Among other things, it has folders with pictures organized with a directory structure by year and by month;  There is a folder for every year (e.g.., 2018) and under every year is an identical list of sub-folders with folder names  1-January, 2-February, ...12-December.  But when I access the shared drive I only see some folders - not all. 

It is very strange - I mean really strange!   for example, for my 2018 year folder, all sub-folders show up!   But for 2019, I only see folders whose names start with 1 (what the ?!); 1-January, 10-Ocotber, 11-November - but for some reason not 12-December.   But none of the other months.   And the sub-folder names under 2018 are IDENTICAL to those under 2018.  It doesn't matter if I only share 2019 (i.e., I do not share the 2018 folder) - I still only see the small subset of folders with leading "1" in the name.   If I go into the share settings and de-select all sub-folders except for one in particular - (For example, 2019=>2-February) then I can see that folder that previously did not show up.  But if I selectd all, or even a few sub-folders in the 2019 directory, it gives inconsistent, funky results - some show up, some do not.  

But 2018, which is the EXACT same folder structure as 2019, shows up just fine.   Lastly - if instead of accessing the shared folder through the media share icon (in Network Locations inb Windows Explorer), I type the URL for the shared fodler directly into the Explorer folder bar (\\share_name) , THEN I can access everything just fine - all the folders show up when I browse the directory tree!!   But I cannot use that trick when trying to view photos from my TV - it only sees the media share on the network, and it sees same funky missing folder view as my computer.   

Would really like a fix for this!

I have exactly the same problem.... Please can you guys fix this. 

Archer AX50 v1.0

Firmware : 1.0.8 Build 20200426 rel.65338(4555)

Here is an example. Notice StarGirl is missing from the top folder.

@Kevin_Z Its not a HDD problem, I have exactly the same problem.

@Kevin_Z  If it is file formats then why are the folders missing? Look what I found today....  I found the missing files but they are in some really weird location. 

This is not where I put these files... and there goes your theory about file types. Please can this be fixed as this is an new device... If not I will return this product for a refund.

@Kevin_Z it's not video formats. I have the same problem on my Archer C5400.

I plugged USB HDD to my router. When I share the whole drive or a specific folder as a media source, I get only few movies available via media server. When I stop sharing and start sharing again the same folder I get different amount of movies. It's always random. I can get only one of 20, the next time I can get 8 of 20 and so on... It's very annoying. To watch the movie I want I now copy it to a separate folder and share exactly that folder. In that case there is only one movie and it is available via media share. As soon as there are more than one movie in the shared folder it gets randomly interrupted during indexing movies. I tried to change names, use only Latin chars, use short names - nothing helps. It's always some random number of movies available out of the shared folder.

Here is my firmware version:

1.2.5 Build 20190411 rel.52981(4555)

ArcherC5400 v2.0

@Kevin_Z 

I have an mSATA SSD drive connected via USB.  The SSD is a Samsung 860 EVO 500GB mSATA Internal SSD (MZ-M6E500BW)