External keyboards are not working right

[Ili4]

I have a problem with external keyboards. I recently bought the Microsoft Wireless Comfort 5050 and sometimes it repeatedly presses a letter e.g. like thiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiis. Sometimes is only stops when I press delete. Another example is that when I press once delete it starts deleting my whole text which is quite exhausting because I always need to search for previous versions of the document as the current one is deleted... Firstly I thought it is a problem with the new keyboard. I reinstalled the driver, I plugged in the dongle in every usb port I have. I ran a malware-scan, spyware-scan and did every advise I read in online forums. I also installed the Microsoft Keyboard and Mouse center and tried to change some settings.
I changed to the Logitech keyboard my parents have and the problem still appears!!!! 

So my conclusion is that my computer must have a problem because I tried 3 keyboards (1 microsoft and 2 logitech) and with all keyboards the same problem appears. They can not be faulty because on my parents computer (asus zenbook) all three keyboards work perfectly fine. I did a HP Hardware Diagnostics test with the keyboard and it didn't find any problem there.

I already contacted HP Support but I didn't receive any help there. They were convinced it was a hardware problem with the keyboard and I should check with Microsoft.... Microsoft also couldn't help me because they said I already tried everything they knew. They assumed it must be a problem with my HP computer as the keyboard works on other computers...

I am quite desperate now as I tried a lot of things. Any other ideas what could be the problem or what else I can try?

[WAWood]

@Ili4 

Not run across this myself -- but there is a feature in Windows that allows you to set the keyboard repeat rate -- and that is all I can think of that might help:  https://winaero.com/change-keyboard-repeat-delay-and-rate-in-windows-10/

[Ili4]

Thank you very much for your reply. I tried it but unfortunately the problem still appears....