The C++ interfaced for the OneCore-API was changed in NVDA 2022.1.1:
Moved the UWP/OneCore interaction layer of NVDAHelper from C++/CX to C++/Winrt. (#10662)What’s New in NVDA
I used the the version and reimplemented automatic language switching. On the way I cleaned up the code and make it work in more cases, when more than one text block is processed at once.
You can find the new version compatible with NVDA 2022.1.1+ here 0.2.0.