[Bug] Nested Region Injection fails on Android in Prism.Maui

[R8MC]

Description

When using nested Regions with Prism.Maui, injection behaves inconsistently across platforms:

On Android, only the first guest ContentView (B_g) is successfully injected into its host Region (A_h). The second guest ContentView (C_g), which should be injected into the nested host Region (B_h), fails silently — the nested host Region (B_h) remains empty.

On Windows and iOS, both injections (B_g into A_h, and C_g into B_h) work correctly as expected.

Steps to Reproduce

1. Place a (host) ContentView A_h on a ContentPage P and assign a Prism Region to A_h (e.g., "FirstLevelRegion").
2. Create a (guest) ContentView B_g that will later be injected into the Region hosted by A_h.
3. Inside (guest) B_g, place a (host) ContentView B_h and assign a Prism Region to B_h (e.g., "SecondLevelRegion").
4. Create a (guest) ContentView C_g that will later be injected into the Region hosted by B_h.

ContentPage P
└── Host ContentView A_h [Region: FirstLevelRegion]
└── Guest ContentView B_g
└── Host ContentView B_h [Region: SecondLevelRegion]
└── Guest ContentView C_g

Platform with bug

.NET MAUI

Affected platforms

Android

Did you find any workaround?

No response

Relevant log output

[brianlagunas]

You need to provide a small and focused sample application that reproduces the issues or this will be closed.

[R8MC]

It gets a bit more complicated. As requested, I’ve uploaded a small sample application illustrating the issue (here: https://github.com/R8MC/NestedRegionsNotInjectableOnAndroidIssue).
In this application, I’m not receiving an OnNavigated event on B_gViewModel under either Windows or Android—even though the INavigatedAware interface is implemented and the view is injected into A_h.

I haven’t checked it on the iPhone yet.