Of course. But, LibreELEC can sometimes boot too quickly for its own good. The "Wait for Network" option is not for the NAS, it's for the LibreELEC device. Other than that, I don't think we can add any more information on that subject.
If the network connection is not the problem, it will be the database connection itself. Double-check your kodi.log file for database connect issues.
This feels llikei have pusuade somebody of seeing an UFO. Why can't anybody in this thread just except that it's just a problem with libre-elec and work on a real solution? Boy this whole discussion is giving me a great feeling about ever giving feedback about a bug... NOT...