Hello - I wasn’t sure what Github repo this should fall into, so I’ll just post it here.
If you try to access the MySensors library page (PlatformIO Registry) you’ll get a brief flash of content and then a 404 error. I assume that’s because they moved their repository.
GitHub - mysensors/MySensors: MySensors library and examples → GitHub - mysensors/MySensors: MySensors library and examples
As a note: One can still pio lib install 548 but it seems to grab an old commit, again, probably because they moved their repo.