This PR goes with #15813 it is just updating a sample TIP to enable reproduciable steps without a full Keyman and keyboard install. Here is the Microsoft Feedback Hub link

Notepad in Windows 11 removes extra unicode char when using the ITfRange interface - Text Services Framework.

This behaviour has so far only been observed with Notepad on Windows 11 other complaint TSF apps I have tested do not behave this way. I have tested a other that use the TSF such as lvirus Text Editor, Word etc.

Steps to reproduce
The project is in keyman\app\windows\src\support\tsf-tip-standalone-test if you wish to checkout and build.
I have attached the output a zip TextService-Step06-3_x64.zip that contains output dll.

• On Windows 11 installation
• Use the command line regsvr32 TextService-Step06-3_x64.dll
• This will add Icelandic Sample Text Service which can be selected from the language bar.
• Open Notepad (Windows 11 version uses richedit)
• Select the Icelandic Sample Text Service
• Type A This should about 'B' to let you know the keyboard has been selected succesfuly
• Copy and paste this text fór which is U+0066 U+006f U+0301 U+0072
• Move the cursor to the right of the ó and press T
• Observe: The ó is deleted and the cursor is now the right of the r

Expected is the just the diacritic is deleted and the cursor is to the right of the o. Leaving for

If you open Word or another TSF compliant application and run the same steps you will observe the expected behaviour.

Note I logged the value of outn after calling ShiftStart to see if Notepad was reporting 2 characters. However, the value was 1. This matched the value set in Word.
if(tfSelection.range->ShiftStart(ec, -n, &outn, NULL) != S_OK)