For Gutenberg, there is https://github.com/WordPress/gutenberg/issues/3218
You can search the issues for one that sounds like your problem and comment there. Or open a new issue.

I am afraid you didn’t understand me.

Here’s what I got: You want the same keyboard shortcuts that you used to have. The new editor has different ones and for different things. That GitHub issue is for customizing keyboard shortcuts, and if the code isn’t merged yet, they are still working on it. If that issue doesn’t exactly cover what you are wanting, you need to write a new issue, so that the developers can see the problem and write some code. If you don’t ask, it doesn’t get done.

Also, you can install the Classic Editor plugin if you prefer those keyboard shortcuts while they are fixing the new editor.