Within Compositions, check your srt drop-down. It has a toggle for setting “Only complete recordings”. May be turned on and therefore limiting the recording to display.
But within that particular release there are 3 recordings, two other symphonies. Your original listing likely only inclludes releases that contain nothing BUT the 9th.
Glad it worked out.
p.s. I would like to see that toggle brought out to the Composition screen level; not buried within a sort drop-down.
It is hidden a bit but it was originally added to help with Opera and Opera excerpts. I normally have it set off but I was looking at an opera the other week and must have forgot it