But why a new keyboard? This keyboard that I am using right now to type this message works perfectly. And it used to work perfectly on that boot recovery screen too. ALWAYS. Only recently it isn't recognized during that boot up selection screen. It's fine after normal boot and works perfectly for all apps and software, etc.
You have a wireless keyboard. It is possible for a wireless keyboard not to work until Windows loads. That is obviously what is happening here.
Although it can happen, a wired USB keyboard is not likely to fail during the initial boot-up phase. The reason I suggested that you try a wired USB keyboard is because that is a very easy (and inexpensive) thing to try.
Even less likely to fail would be a PS/2 keyboard. But it is not likely that you have PS/2 ports on your computer, or that you could locate a PS/2 keyboard. (PS/2 is old technology.)
You have been fighting this issue for days. If you had plugged in a wired keyboard, and if that would have worked, you would have solved this issue immediately, rather than still pulling your hair out over it. What would you have preferred, to spend the +/- $10 for a cheap keyboard and perhaps solve the problem immediately, or not spend the money and still be fighting with the issue over a week later? For me, I'd rather try the other keyboard, because my time is worth more to me than $10. But I have two computers, so I can swap keyboards if needed.
I gave you the same suggestion that I would have followed. But you are free to try other things, if you want. The problem is, there aren't too many other things you could try. And my decades of experience in this field tells me that plugging in a wired keyboard would lead to a quick solution.