Custom soundscapes can't be loaded from the .bsp in Multiplayer

Everything works fine in Singleplayer, both for myself and other players. However, testing the map on a Listen / Dedicated server
results in them hearing random crappy HL2 soundscapes.

Here’s what I did:
Added custom sounds in the map file
Included the soundscape manifest (scripts/soundscapes_ttt_avalanche_a2.txt) + the custom soundscape used in it (scripts/soundscapes_tflippy_avalanche.txt)

Sending these two files to players (renamed to soundscapes_manifest.txt and soundscapes_tflippy_avalanche.txt) and installing them in a scripts/ directory fixed it, but it’s useless,
as most server owners aren’t even aware of the soundscapes’ existence.

Some other people having the same issue.

I thought soundscapes were broken, I couldn’t even get default ones to work