The issue is that gocryptfs mountpoint is not visible when the directory is browsed through samba. Take a look at this github issue: https://github.com/rfjakob/gocryptfs/issues/264 The way to fix the problem is to use the -allow_other option when mounting, as suggested by the upstream developer in the github issue thread. However, there is no way to do this currently from the Plasma Vault interface.
Sounds like we should just use -allow_other as a default CLI arg.