Explorer showing duplicate files/folders on a network drive

On my Fritzbox 7490 router, it has a feature where you can plug in a USB drive and it will be available to all users of the network in a NAS-like way.

For the last couple of months (but never before that) I'm seeing duplicate files and folders, Sometimes two instances of each folder or file, and sometimes three instances. I permanently have an explorer instance open to that drive because I use it so often. Ignore the fact that other machines have potential access to it, because my laptop is the only one that does ever use it (and is 99.9% of the time the only computer switched on).

I've made a screenshot below of what it looks like. It is of course impossible to have multiple files or folders of the same name, but Explorer is happy to present the folder hierarchy as if that is what's happening. You'd think it would catch itself and realize that can't be right, but it doesn't. If I hit F5 to refresh, they'll usually go away and I'll see single entries as normal, but quite often they don't.

One important and perhaps relevant thing to note is that I have a batch file that is constantly running/re-running and when it detects files of a certain type, it will copy them from my local drives to that network drive. So my machine will have two parallel (and different) connections to the drive. But .... and it's a big but (I cannot lie) I've been using this machine and that batch file since I bought the laptop 3 years ago without this duplicate entries ever happening. I suspect a windows update change to Explorer (or some service) that happened in the last 6 months.

Is it just me?

Using Windows 11 Home 24H2 26100.3194

I suspect an issue with the Fritzbox. Does this isuse go away if you have only 1 active connection to the drive?

neemobeer said:

I suspect an issue with the Fritzbox. Does this isuse go away if you have only 1 active connection to the drive?

Click to expand...

That's a good point, the Fritzbox has the ability to auto-update its firmware whenever it feels like without informing me unless I happen to login to the admin screen, which I typically don't.

Yes the issue is also happening with only 1 active connection. I stopped my auto-rerunning batch file, stopped VLC which was playing a video from that drive, and closed explorer so that I then had no active connections to it. Then relaunched Explorer and opened a couple of subfolders and there were the duplicates. One of the top level folders was there in triplicate, child folders were there in duplicate but if I went into one of those triplicate folders, I would see the subfolders singular. So on the left they were duplicated (in the tree view) but on the right they were not (in the file/folder view in the main content pane.

I blame either the Fritzbox or Explorer accessing network drives, because it doesn't happen to any USB drives directly plugged into my laptop. I don't have any other kind of network shares I can look at to test on.

I would reboot the Fritzbox to make there are no connections from other devices.

I've never experienced that behavior in explorer in my many years in IT with a multitude of network based storage technologies

neemobeer said:

I would reboot the Fritzbox to make there are no connections from other devices.

Click to expand...

neemobeer said:

I've never experienced that behavior in explorer in my many years in IT with a multitude of network based storage technologies

Click to expand...

I forgot about an Android tablet that had previously browsed to the drive, so shut that down, then rebooted the router. As soon as it had come back up, I went straight to Explorer to point to it, and instantly all the folders were double-entried. It's most bizarre

Same for me btw, I've been using Explorer since Win95 and never seen anything like it. I've just been to the Fritz forums and cross-posted there.

The problem is now gone !!!!!

Got myself a Synology DS124 NAS and sharing that USB SSD from it is giving me 10x the performance I was getting from that same drive via the router's NAS function. Instead of 3-4MB/s I'm now getting 37MB/s which for now is perfect.

I was surprised I had to install a drive inside it as well, I assumed it would use a ROM and a RAM for its OS and caching purposes, but no, it demanded another drive. Luckily I had a small (128GB) SSD that I wasn't using anymore so popped that in there. So if anyone's reading this in the future thinking you can use a DS124 plus an external USB drive and that's the whole story, it's not. Very happy though, the entire solution only cost me €149 and considering I'm self-employed, the taxman will effectively pay for half of that