Does Narrator reading order diverge when third-party apps implement UI Automation incompletely?

Answer

Yes, Narrator reading order can diverge when third‑party applications provide an incomplete UI Automation implementation.

Likely explanation

The divergence stems from missing or misordered Children collections and absent required properties such as ControlType, Name, BoundingRectangle, IsOffscreen and HasKeyboardFocus. Without these, Narrator cannot reliably map focusable elements, leading to skips, repeats or jumps.

Confirmed facts

• Windows 11 builds 22H2 through 24H2 on x64 and ARM64 exhibit the issue.
• No public API exists to query UI Automation completeness at runtime.
• Registry changes to force MSAA fallback are unsupported and may cause instability.

Steps to verify in this case

1. Run a short script that uses the UIAutomationCore COM interface to enumerate the root element of the target application and list each node’s ControlType, Name, BoundingRectangle, IsOffscreen and HasKeyboardFocus values.
2. Compare the scripted element count with the visible UI captured by Microsoft Inspect; mismatches indicate incomplete automation.
3. If the script shows correct Children ordering but Narrator still misbehaves, request the application’s UI Automation provider class ID or source code to refine diagnosis.

Mitigation for end users

Enable Narrator’s “Read from top” mode, use Microsoft Inspect to view the automation tree, employ third‑party accessibility validators, or apply a custom UI Automation provider if the vendor permits. Legacy MSAA fallback is unsupported and should be avoided.