Pro Tools remembers two different fader levels for monitoring each audio track: one for when the track is record-enabled, and one for when it is
not record-enabled.
Pro Tools keeps track of these two states for fader levels automatically. If you adjust a fader when a track is record-enabled and then turn off record enable for the track, the fader returns to its playback level.
When audio tracks are record-enabled, their volume faders in the Mix window turn red, indicating that the record monitor level is active.