The delete key is no longer working in Word

Thank you very much for all this information. I thought I was finally going to be rid of this bug, but unfortunately, the current key is indeed "del" or "supp." I reset all the default shortcuts, and I still encounter this problem.
Still, thank you very much for this lead.
In fact, I just realized that I wasn't precise enough in my post. The "del" or "supp" key works, it's the backspace key that doesn't work, the one above the enter key, but it doesn't work only when I highlight a paragraph to delete it. Similarly, if I want to replace some words with others copied from somewhere, before I would highlight and paste what I wanted in place, but now I have to highlight, press delete, and paste the new text. I work a lot on Word, and these additional steps waste my time. Thank you.

I specify that it is only a problem in Word because, for example, with Open Office it works as usual.