Invisible Objects Greyed Out in Outliner, but they are not "Hidden"

Hi all,
I cannot figure out how Objects in my outliner are greyed out, not visible in the model, but still “Visible” according to the eyeball. I cannot see the objects unless I double click on the group in outliner, after which they appear, but when I escape the group it disappears again.

See objects labeled as “warehouse” in the outliner:
image

Can anyone tell me why this is happening, and how to make the objects visible?

There is an expansion arrow showing in your screenshot, so other parts are involved, so some are hidden some aren’t hence the grey eye icon.
Add your model for a specific answer.

The greyed out objects have a Tag that is set to non-visible in the Tag panel. The eyes in the outliners do not overrule them.