change input source not working

I have macbook air m1, where normally i can change input source with the fn key on the keyboard. But when I start using it (doing translations) then after some time (half an hour maybe) is stops working.

I can then change the key's function so that is shows emoji, at it works fine, but when I change it back to input source changer, it doesn't work and only thing I can do to fix it is to restart my computer. Is there any other way to fix it? Why is that happening?