Backups to SVTL media hang in "Waiting for media" with "No media request" (4047868)

A large majority of jobs targeting SVTL media remain in "waiting for media".
Diagnosing the Media Request gives a pop up window indicating "No media request".
In Media Management all SVTL tapes that should be full, show "99% used, 510KB space left".
As a result, any job that is assigned such tape (with 510KB free), will hang in "Waiting for media" with no media request.
The job is hung in a loop trying to write with no space, instead of trying other media.

Targeting blank SVTL media completes successfully.