In multiplayer, the teleport button in the inventory updates for all players whenever a player activates a waystone. So if Player A activates a global waystone "Fooville" then the inventory teleport buttons for Player A, Player B, and Player C (and anyone else on the server) become "Fooville". The teleport button is set to return only, but my impression was that it was per-player.

Config can be found here but most relevantly I have:

# If enabled, the teleport button will only let you return to the last activated waystone, instead of allowing to choose. B:"Teleport Button Return Only"=true

Waystones version is 4.1.0 for minecraft 1.12.2 and the modpack is my own custom pack with the permissions page on technic having all the present mods listed.

Since the return functionality has changed in 1.14 to instead pick the closest waystone, the issue no longer persists there. However, 1.12 is only getting critical fixes at this point and the return button never really worked well in the first place, so it's unlikely that this will be fixed for older versions.