Between Audacity 2.4.2 and 3.1.3, upstream changed how Audacity finds FFmpeg. It no longer links to it but instead loads it at runtime:
https://github.com/audacity/audacity/issues/2161 I detailed my hapless attempts to do that in the upstream bug report: https://github.com/audacity/audacity/issues/2489 Any advice is most welcome!
