Audacity has recently (I'm not sure when exactly) stopped being able to import / load some wav files

I get a window on screen

"Audacity did not recognise the type of file 'MONO-001.WAV'.
Try installing FFmpeg. For uncompressed files, also try File > Import > Raw Data."
This was working earlier this year - the file is from a Zoom R16 Multitrack recording device, and I was recording audio from various Synthesizers for "Lockdown" videos my band was releasing

Those files no longer load into Audacity

The wav files are

file MONO-001.WAV 
MONO-001.WAV: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 44100 Hz
The "build information" tab in the Help > About Audacity tells me

ffmpeg (FFmpeg Import/Export) Enabled

I've also loaded the files into audiacty on a LinuxMint VirtualBox VM, which has Audacity v2.1.2 and it loads and plays fine

Audacity in Tumbleweed is

Information for package audacity:
Repository     : openSUSE-Tumbleweed-Oss
Name           : audacity
Version        : 2.4.2-2.2
Arch           : x86_64
Vendor         : openSUSE
Installed Size : 17.0 MiB
Installed      : Yes
Status         : up-to-date
Source package : audacity-2.4.2-2.2.src
FFmpeg is version 4

Information for package ffmpeg-4:
Repository     : packman
Name           : ffmpeg-4
Version        : 4.3.1-6.2
Arch           : x86_64
Vendor         : http://packman.links2linux.de
Installed Size : 2.2 MiB
Installed      : Yes (automatically)
Status         : up-to-date
Source package : ffmpeg-4-4.3.1-6.2.src

Audacity depends on FFmpeg-4 ie removing FFmpeg-4 automatically removes Audacity, re-installing Audacity re-installs FFmpeg-4

So I'd guess there is something broken about the way Audacity uses FFmpeg-4 (or doesn't use it)

And, for the record, using FFmpeg manually to convert my WAV file to mp3 works fine, and the converted mp3 file loads into Audacity with no problems

ffmpeg -i MONO-001.WAV -ab 192k MONO-001.mp3