Editing First Nav or moving nav to first nav results in subnav disappearing.

[Necrophyte]

So I went to add Home to my Nav. In doing so, the subnav bars completely disappeared.
When I go to edit them, they re-appear. Only to disappear again when I finish editing.
I can create a new Nav. I can even move the Nav around as long as its not to the first position.
Editing the first one, or moving any of them to the first position. Results in the subnav bar to disappear.

Anyone know a fix for this?

Running 5.2.3, upgraded from 4.2.3

[Necrophyte]

This is still a problem.

[Necrophyte]

Attempting to do this again as I wanted to add something. This is still happening. Now the sub menu goes empty as well. This is with the unchanged 5.2.3 Template. This only happens when you move it to the first position. You can add as many as you want in any place, but the first position. Soon as you do. Its gone. One have anything to fix this?

[Necrophyte]

Nope wait, I finally understand now. Each tab has its own possible subnav. Amazingly simple, was over thinking it, and I feel really really stupid right now.

[Mark.B]

Nope wait, I finally understand now. Each tab has its own possible subnav. Amazingly simple, was over thinking it, and I feel really really stupid right now.

Theory behind that is that you have context-aware links in the sub navbar. So the links shown in, for example, Articles may be different to those in Blogs.