"mHostView.addView adds the react views to the modal. The modal is a wrapper around react views. They are added to the modal.
mDialog.setTitle does not display the title. The react-native implementation must have changed the functionality. Commenting addTitle creates issues.
Try to call setTitle on the Activity (the Dialog is included in a Custom Activity)
Investigate PhoneWindow.setTitle in particular onWindowTitleChanged and dispatchWindowAttributesChanged
UPDATE: The method is WindowManager.setTitle"

"https://github.com/fabriziobertoglio1987/react-native/blob/62f83a9fad027ef0ed808f7e34973bb01cdf10e9/ReactAndroid/src/main/java/com/facebook/react/views/modal/ReactModalHostView.java#L114
https://github.com/aosp-mirror/platform_frameworks_base/blob/e648d3cb91f9a0156c729ca18ec27e71f59f9ce2/core/java/android/view/WindowManager.java#L3794"

"Read TalkBack logic around dialog and title.
Research for string associated with the Dialog role
Research for logic related to the title attribute"
Read logic mDialog
https://github.com/fabriziobertoglio1987/react-native/blob/62f83a9fad027ef0ed808f7e34973bb01cdf10e9/ReactAndroid/src/main/java/com/facebook/react/views/modal/ReactModalHostView.java#L285

Read logic from AOSP Dialog, Window and WindowManager
https://github.com/aosp-mirror/platform_frameworks_base/blob/e648d3cb91f9a0156c729ca18ec27e71f59f9ce2/core/java/android/app/Dialog.java#L641
https://github.com/aosp-mirror/platform_frameworks_base/blob/e648d3cb91f9a0156c729ca18ec27e71f59f9ce2/core/java/android/view/Window.java#L1444
https://github.com/aosp-mirror/platform_frameworks_base/blob/e648d3cb91f9a0156c729ca18ec27e71f59f9ce2/core/java/android/view/WindowManager.java#L3801

"Quickly test the following solution:
Implement prop accessibilityTitle
Implement method DialogManager accessibilityTitle
Call mDialog.setTitle(“my title”)
The setter method setAccessibilityTitle is not called"

"The setter method setAccessibilityTitle is not called, while the other props are called:
Read other files in the same folder
Read cpp fabric files
Add fabric configurations
Read reactnative.dev codegen instructions"

"Troubleshoot codegen generation of the accessibilityTitle prop.
The prop is not added to jave codegen files generated in ReactAndroid/generated/codegen/Modal. Make sure the prop is added and test the outcome:
Read instructions on reactnative.dev on codegen types to use for this prop (optional)
Codegen does not include accessibilityTitle prop. Make sure codegen adds the title.  
Try testing on Paper. If the issue does not reproduce on Paper, it is caused by a missing CPP prop configuration"
https://reactnative.dev/docs/the-new-architecture/pillars-codegen

- use Stringish instead of string (internal type used in react-native)
- add Nullable to Java setAccessibilityTitle, we use setTitle(null) to
  clear and previous value

changes discussed in
facebook#34969 (comment)
which consist in:

- Modal accepts prop TitleComponent which is a React.Element or
  Component and represents the title of the modal.
  The solution is taken from ListHeaderComponent in VirtList
- AccessibilityInfo.sendAccessibilityEvent is triggered to focus on the
  Title when the modal opens
- sendAccessibilityEvent needs to set a timeout of 1s (see facebook#30097 and https://stackoverflow.com/questions/28472985/android-set-talkback-accessibility-focus-to-a-specific-view)
- TitleComponent Styling and positioning is defined outside of reactnative
  This has to be reviewed as ListHeaderComponent uses
  ListHeaderComponentStyle

Notes:

"Improvements:
Trigger focus on components using Fabric API (findNodeHandle is deprecated, setAccessibilityFocus). setAccessibilityFocus has several issues (stackoverflow), and I can not set a ref on a modal.

componentDidMount seems to trigger before rendering the Modal children, the lifecycle does not work correctly with a modal on Fabric.

You need to use forwardRef to call sendAccessibilityEvent
Need to change the way you create the title component so that you create a forwardRef and then use this to send the accessibility event"	"https://reactnative.dev/docs/new-architecture-library-intro#preparing-your-javascript-codebase-for-the-new-react-native-renderer-fabric
https://reactnative.dev/docs/accessibilityinfo#setaccessibilityfocus
https://reactnative.dev/docs/new-architecture-library-intro#preparing-your-javascript-codebase-for-the-new-react-native-renderer-fabric"
"Test Text component solution without using getNativeRef, as the problem could be caused by timeout and not ref. Check the keys and try to use the _nativeRef
Implement getNativeRef for the Text component and use it in Modal to call setAccessibilityFocus"	https://github.com/fabriziobertoglio1987/react-native/blob/accbbfc01af57eda34374ce3b13e36b6e7c12a93/Libraries/Components/TextInput/TextInput.js#L1213
"Adding setTimeout with a wait of 1-second fixes issues with setAccessibilityFocus does not onLoad

The reason is triggered focus on other elements, so we need to use an API to wait for the focus to display on that element

Try to use runAfterInteraction"	"facebook#30097
https://reactnative.dev/docs/next/interactionmanager#runafterinteractions"
"Review meeting notes and Brett suggestion
Consider removing the sendAccessibilityEvent as violates WCAG 2.0 regulations, including 3.2.1 and 3.2.3"
Test Android
"-  The title component displays under the Modal on Android.
The title receives focus with the ModalPresentation example.
The title does not receive focus in the ModalOnShow example.
=> In both examples, the titles displays under the modal
=> In ModalOnShow, the title does not receive focus
Apply the same prop as in the ModalPresentation and see if the title receives focus
Remove style
Put the title directly in the ModalOnShow and trigger the focus
Trigger the focus manually with a button instead of using useEffect( _ref )
Trigger focus manually with a button in the Modal.js"
"setAccessibilityFocus correctly moves the focus when triggered with Button. The issue could be caused:
ref is undefined
read conversation facebook#30097
alternative callback to _showModal (onLoad)
TalkBack moves focus after calling sendAccessibilityEvent => increase timeout"	facebook#30097
"Test functionality on iOS:
test functionality on iOS with Xcode build"
"Improve solution and finalize diff before final commit:
Fix issue with sendAccessibilityEvent based on stackoverflow solution or runAfterIteraction (setAccessibilityFocus does not onLoad)
TitleComponent should move to rn-tester ModalPresentation and ModalOnShow
forwardRef may not work"	"https://github.com/fabriziobertoglio1987/react-native/blob/accbbfc01af57eda34374ce3b13e36b6e7c12a93/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/SurfaceMountingManager.java#L968
https://stackoverflow.com/questions/28472985/android-set-talkback-accessibility-focus-to-a-specific-view
facebook#30097"