Keyboard recognized but not typing

Hello,

My computer is acting strangely.
I first encountered problems with my keyboard. When the computer first starts up, my keyboard works normally, but generally after a few minutes, it no longer allows me to type and only lets me interact with the windows on the screen, even though I haven’t done anything special.
I’ve plugged in a second keyboard with which I’m currently typing.
My computer and my main keyboard are about 2 years old. My keyboard is a Corsair K55 RGB Pro Gaming Keyboard.

I’ve checked the drivers; they are up to date, everything seems fine. Regarding my keyboards, the IHM keyboard (the one I just plugged in) is recognized and everything seems normal, however, the Corsair does not appear in the window for updating drivers (Device Manager), but it is recognized by the computer.
I have run virus scans which found nothing (I am using Kaspersky).

The Sticky Keys are disabled, the On-Screen Keyboard is disabled.

I am in training, an online training, and I am currently using this computer only for that purpose. I am downloading videos for my classes, and documents as well. This is a course offered by Google. Once, when I wanted to create a Word document, it went into protected mode for no apparent reason; that was a few days ago (yesterday or the day before), it seemed strange to me but nothing more.

Just before writing here, my computer logged me out of my session. I had to enter my password to log back in, but it wasn’t working and an audio message was starting, if I understood correctly, to switch the keyboard to accessibility mode. I restarted the computer, and that worked.

Do you have any suggestions for avenues to explore?