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?