Bad luminance when assign a clip to a Group

Hello,
i've got something strange with some clips.
I've a Multicam (2 cams, closeup & large),
2 Groups created, in the Way to easily color grade each one (in both by using Group pre-clip),
Cam1 (Group closeup) is ok along all the timeline
Cam 2 (Group large) is ok only for first clips. As soon as I assign some rest of clips to this Group, They appear washed out.
I've tried to de-assign, and reinitialized nodes, re-assign, purge cache etc..
Nothing change, Same Problem.
Need some help on that.
Thanks in Advance
David
DVR17

Why don’t you open yourmulticam clip in the timeline and grade both of the clips as a whole?

Why don’t you open yourmulticam clip in the timeline and grade both of the clips as a whole?

I'd assigned all clips in the Same Group (wich is fonctionnal) and voilà !
Fortunately, both camera are indentical, and it's settings too, skin is ok, according to both color checker from cameras, and in the vectorscope, after change a Little bit hue.
That's was my Target, matching cameras.
Problem occurred on one Group because I did a lot of tests on this timeline I guess.
Hope it is rare.