VCA Tracks were added to Pro Tools 12.2 (non-HD), but when opening a session containing VCA Masters that are not set to 0 the Session Notes state:
"This version of Pro Tools does not support VCA Masters. This session was previously saved with VCA masters that contributed automation to the session. The VCA masters will be dropped, but their data has been coalesced into the slave tracks."
Adjusting the VCA Master will cause grouped Audio, Aux, and Master faders to jump.
Until a fix is issued, Avid recommends going back to 12.1 to work on sessions containing VCAs.
See http://duc.avid.com/showthread.php?p=2291439 for a possible workaround (thank you Steviebhoye).