Hi,
You can find the most common settings that need to be checked in the troubleshooting list pinned to the top of the forum.
Still, my guess is, that the problem is simply the OS.
FxSound was made only for Windows, and people have tried forcing compatibility before several times, but the outcome is always the same - there just seems no way to make FxSound work on Linux, no matter what.
You can run a forum-wide search on the term “Linux” through the magnifying glass at the top right to see all the previous threads on this topic.
And this is the GitHub feature request to develop FxSound for other operating systems, in case you’d like to keep track,