Replay Gain not showing

I have 2 clips, both with the latest firmware 1.01.35.  For some unknown reason, Replay Gain appears in Music Options in 1 clip, but not the other.  I noticed that there was a “Music EQ” option as well as a separate Equalizer option in the clip with the missing Replay Gain feature.  After I formatted & Reset the clip, the “Music EQ” disappeared, leaving the regular Equalizer option.  However, “Replay Gain” still does not appear.  How can I get “Replay Gain” to appear?