Bug Report: Find and Replace Functionality Issue in Notepad++

Bug Report: Find and Replace Functionality Issue in Notepad++
Description:
The Find and Replace functionality in Notepad++ appears to have a bug when utilizing the Extended search mode. Specifically, when attempting to find and replace occurrences of the string \t\r\n with \r\n, the search mode fails to function as expected.

Steps to Reproduce:

Open Notepad++.
Access the Find and Replace dialog (Ctrl + H).
In the "Find what" field, enter \t\r\n.
In the "Replace with" field, enter \r\n.
Ensure that the Search Mode is set to "Extended".
Click on the "Replace All" button or perform a step to initiate the replacement process.

Expected Behavior:

The Find and Replace operation should locate all occurrences of the string \t\r\n in the text and replace them with the string \r\n.

Actual Behavior:

The Find and Replace operation does not function correctly when using the Extended search mode. It fails to find and replace the occurrences of \t\r\n as expected. No replacements are made.

Start by reproducing the issue in Notepad++'s Find and Replace dialog, opened with Ctrl+H, using Extended search mode and the stated find and replacement strings. Trace the search and Replace All entry points to determine why the tab and line-ending sequence is not matched; done means all occurrences are replaced as expected.