Keyboard only works after several PC starts

[PCM98]

1) After starting PC it needs more and more time until mouse cursor appears and mouse works.

2) Only sometimes keyboard works after start. Most time keyboard doesn't work after first PC start. With mouse click PC shut down and then again start. After second or third PC start keyboard most time works.

When keyboard works then no problem during session but after next PC start most time same problem.

HP PC Hardware Diagnostics found no problem. Keyboard and mouse are original hp.

After changing USB slot same problem at the next start.

What can I do?

[Prométhée]

Hello
how long have you owned the computer ..?

https://support.hp.com/my-en/document/c05347319
it is mentioned
Release Date
28-Nov-2016
Has it already been reinstalled?
How much space is available on the primary SSD?

What is the exact windows version
type winver, in the search bar

[PCM98]

Hello Prométhée,

I bought the computer new (first user) at the end of 2016.

No reinstallation, free space on SSD >100 GB, Windows 20H2.

[Prométhée]

The last update 20h2, is a problem for many computers
Do you know if you have this problem since this update or not there was already a problem before?

[PCM98]

Update 20H2 was nearly 5 moths ago, I think the problem is not so old and came later.

[Prométhée]

So you have no idea if the problem arises after something particular
A new installation, handling?
you have an SSD originally, it is quite fast ....
What you indicate seems to be a problem that one might encounter with a conventional HDD.
In fact it is not a problem of the keyboard or the mouse directly, it is just the time that the computer is ready to work, if it is not ready, nothing else can be done.
Try booting in safe mode, is that better?

[PCM98]

But booting in safe mode would be no permanent solution. Maybe I must wait a little bit longer with keyboard input?
Thanks anyway and best regards.

[Prométhée]

It's just to check
if it works in safe mode, you may just have a software problem, or a driver problem
We can try a few tricks, but here I do not have the computer in hand, it is necessary to check certain points.