Are there any problems with switching layouts with PuntoSwincher in macOS Big Sur?

Question

macOS

Greetings.
After switching to BigSure, how strange PuntoSwitcher works. I don’t even suspect what it is connected with, but I noticed that sometimes it switches only part of the word, namely the first three letters. If the English layout is enabled and I write in Russian, then the first three letters will be English, and the rest will be Russian or something else. I will give an example (the Russian layout is on, I write "hello" and "hello" alternately in the line and this is what happens:

привет руддo привет hello ghbвет hello ghbвет hello

Any ideas why this is and what can be done about it?