I have the same problem for a long time.
Something changes my keyboard back to English all of a sudden and it forces me to use windows key+ space to fix it back to Portuguese..
This is rather annoying since I work with important texts and sometimes in the middle of them the keyboard changes and I write wrong characters until I notice them, if I notice them before pressing enter.
Running 3rd party OS controls doesn't sound pertinent as this happens in all my Windows X machines that were installed from scratch/ virgin.
Best regards,
- Gabriel da Silva