Premiere not recognising proxy media

Hi there

I've recently installed Premiere for the first time on Windows and I'm having an issue with proxy media. I've set up a test project with two clips to demonstrate this in the pictures here.

After creating the proxies, they appear to be attached with the correct file names, and have the blue icon visible in the sequence when I toggle proxy media on in the program monitor.

However, it doesn't appear to make any difference to playback, and when I right-click on the clips in the sequence and select 'Reveal in Explorer', it links to the original media file, not the proxy file, regardless of whether proxies are toggled on or off.

Proxies are enabled in the project media settings. I also have the same issue on another Project, which I've just taken over from another editor, which previously had working proxies, so I'm wondering if there's another setting on my own system which could be causing the issue. I even uninstalled and reinstalled Premiere but that didn't change anything.

Is there something obvious I'm missing? I've attached some photos below to help illustrate the issue.

Thank you!