Question Automatic Navigation Changes Canvases When Using Screen Space - Camera

I'm trying to use the automatic button navigation with the Input Actions Event System. But I'm also trying to use Screen Space - Camera so that I can apply Post-processing to the UI. But it chooses to navigate to different buttons that are on different canvases. I want it to only navigate to buttons that are on the same canvas/gameObject.
It works as intended when using Screen Space - Overlay.

-I have an empty GameObject "UI" with multiple child canvases, each with their different menus.
-My camera uses the UI layer as it's culling mask, while a different camera has everything else. The projection is Orthographic.
-I'm navigating with the Default Action Asset/UI.

 

Pretty sure you would need to not use automatic navigation but instead set up what you want between the

Selectable

s on your canvas(es).

If you are unable to achieve what you want that way, then the last resort would be a script that contains a list of selectables and knows how to switch between them as you like. This would involve turning off all UI navigation and just doing it yourself.

 

That would be what I would do, if it didn't work for Screen Space - Overlay canvases. Because that leads me to believe that there is some variable that needs to be changed somewhere, otherwise, why would it work?

 

Well, the source code is available... for instance this file:

https://github.com/Unity-Technologies/uGUI/blob/2019.1/UnityEngine.UI/UI/Core/Selectable.cs

has an interesting method called FindSelectable() that takes a direction.

That might be a place to begin your investigation.