I downloaded it again on my Mac to test it...
- /Users/<USERNAME>/Library/Application Support/Aerofly FS 4/scenery/airports/eu_ch_airports___FS4-AIRPORTS_20240325
... and it works for me in the path you specified.
In any case, I recommend shortening the downloaded directory name, e.g. to:
- /Users/<USERNAME>/Library/Application Support/Aerofly FS 4/scenery/airports/ch
Then it should look like this:
And that should work -- at least it works for me.