Q libv only shows tapes that are in your library - once DRM spits the tape
out, it won't show up there.

Q vol only shows tapes that are in storage pools.

Your tape is some other type, probably a data base backup tape (since DRM
spits those out along with the copy pool tapes, by default.)

Non-storage pool tapes are defined in the volume history file.

Try this:  q volhist type=dbb

It will show up there if it's a data base backup tape.
But don't try to check it in or get it back; a DBB tape should go offsite
along with your copy pool tapes.  They are worthless without a data base
backup!