Z9 in Nauticam w 180º viewfinder

Got a Z9. Shoots as represented outside the housing. I selected menu options to turn OFF battery save and to get previews through the viewfinder and on the LCD. OK, outside the housing. In the housing, not. No LCD, and the viewfinder goes dark between shots. Viewfinder view is also dark when working and puts a pink tint on subjects. Only in the housing (Nauticam with 180º). Thoughts? Can't tell at depth if I'm getting shots--only on download. Did a factory reset. Z9 still works as it should, will test in water soon. Baffled. 

Does the housing have a connection with the button on the left side of the viewfinder housing? This allows one to switch between screen and EVF manually like with the Z6 and Z7 series. As well there are additional menu-level customization. One can set the EVF to always be for on shooting and the screen for chimping and menu use. There is another setting for reducing the EVF image size that is there for glasses wearers that might also be be good for underwater use.

The sensor that drives automatic switching between the EVF and screen is just above the eyepiece. This is likely blocked by the UW housing or the extended UW viewfinder hence my suggestion of using the manual button above. As well, Nauticam has recently introduced new viewfinders. Their descriptions lack the details need to evaluate whether one of these will help your problem or not.

*tom beat me to it but:

if you have it set to giving you a feed in both VF and LCD, inside the housing, the camera is going to register the viewfinder as being your eye pressed up close to the VF so it will switch to that automatically. With mirrorless, in the housing you either have to choose VF only or LCD only.

those cameras also come with the viewfinder automatically set to show 'live feed'. the what you see is what you get. THat is useful on land but not underwater so turn off live previews wherever that is in the menu

Yes, do NOT use exposure simulation!!!! This is a major problem when using live view in a DSLR IMHO.

You want menu item d8 set to "adjust for ease of viewing", there's also a viewfinder brightness control option, but try the d8 adjustment first.  You'll also want to disable eye detection  at the EVF - though I couldn't find that function in the menus. 

The LCD is likely locked out by the eye detector at the EVF, you should be able to manually switch between the two.  With my mirrorless I tend to use the EVF for everything- including image review, the viewfinder with diopter adjustments gives the best view for me.

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