Multiple versions of a song play at different volumes

[Scottes]

I have two versions of an album, with the songs ripped as FLACs.
All songs have been replaygain'd using Foobar, using "Scan selection as albums (by tags)"
MM does show the track and album leveling adjustments, which are different for each version of each song.
MM is set to "Level Playback volume to" 89dB
Clipping Prevention is Enabled.

If I listen to the first track from each albums, they play at (noticeably) different volumes.
Since they're both the same song, I'm expecting them to play from MM at (approximately) the same volume.

Am I doing something wrong, missing something, or do I just have the wrong expectations?

[Guest]

The latter.

[Lowlander]

The files were analyzed outside of MediaMonkey?

Are you using per Track or per Album for level playback and is Play > Level Playback Volume enabled?

[Scottes]

is Play > Level Playback Volume enabled?

And there's the winner. This wasn't checked. Thanks!