urgent 5.1 question

hi i’m mixing a project in 5.1
all was ok then i realise some stereo traks goins to some 5.1 groups themselves going to some 5.1 output don’t have automation on the Rear Pan …
the track display a 5surround panner that i can use. i hear sound giong in all speakers
all automations are stored and playing back but the Rear panner automation looks grey" “R” is not green and i can’t get it to work.
i tried on/off automation pannels on panners nothing work.
is that a bug ?