Are the grey tanks connected or drained separately?

[Bunkhouse Bandit]

2017 Forest River Wildwood Heritage Glen Hyper-Lyte 24BHHL

Can anyone help me? I supposedly have two grey tanks on board. The dump valve only has a pull handle for 1 grey tank and the black tank. Is there a separate handle or valve for the second grey tank?

My control panel is showing that tank#1 is 3/4 full but I can't seem to empty it.

Thanks,

[Blank]

On my Coachmen I had two gray tanks, large for bath and shower and small for kitchen sink. One black and a gray by the dump station. 2nd valve was about 3-4'away and below the kitchen area, came into the dump area into a T