When looking for the available modules matching a symbolic version targeting a directory, all aliases and virtual modules in the directory are missing from obtained result. Only the regular modulefiles are returned.
It could be reproduced with a mod directory containing a bare 1 modulefile and a .modulerc file defining symbolic version, alias and virtual module:
$ cat mod/1
#%Module
$ cat mod/.modulerc
#%Module
module-version mod sym
module-alias mod/alias mod/1
module-virtual mod/2 ./
With a regular avail search on the module name, everything is correctly found:
$ module av -t mod
/path/to/modulefile/mp:
mod/(sym)
mod/1
mod/2
mod/alias
But not if avail search is performed on symbol:
$ module av -t mod/sym
/path/to/modulefile/mp:
mod/(sym)
mod/1