Search Input Component Disappears After Language Change When No Results Found #10281

Environment:

• ABP Framework Version: 9.3.1
• Angular Version: 20
• License Type: Commercial

Description: We are experiencing a UI bug with the LeptonX sidebar search component that occurs after changing the application language when no search results are found. Steps to Reproduce:

1. Launch the application with default ABP + Angular + LeptonX configuration
2. Observe the left sidebar menu displaying available routes correctly
3. Use the language switcher to change the application language (e.g., from English to Spanish)
4. Open the search bar in the left sidebar menu
5. Enter a search term that produces results → Search works as expected
6. Enter a search term that produces NO results → The search input element disappears completely from the DOM
7. Attempt to change the language again → The search input remains missing
8. The only way to restore the search functionality is to perform a full page reload (F5 or browser refresh)

Expected Behavior: The search input should remain visible and functional even when:

• No search results are found
• The language has been changed
• Multiple language changes occur during the same session

Actual Behavior: Once the search input disappears after a failed search, it becomes permanently unavailable until the user performs a full page reload. This forces users to refresh the entire application to restore basic search functionality.

Additional Information:

• The problem specifically occurs only after changing the language at least once
• If search results are found, the component remains stable
• The issue persists across multiple language switches once triggered
• Browser console shows no JavaScript errors when the issue occurs

Could you please investigate this issue and provide guidance on whether this is a known bug or if there's a recommended approach to prevent this behavior?

The error also occurs in the official demo: https://demo.abp.io/