My keyboard (numpad) overwrites everything I have a Mac mini with High Sierra (10.13.4) with a Windows-keyboard (it has a numpad).

Everything went fine for a long time but a few months ago I got a big problem: In many apps (Calculator, Excel, etc.) when I want to write for example "567" with the numpad, the number I push overwrites the last number. So if I push 5, 6 and 7, than instead of "567" it just shows a 7 (because the 6 overwrites the 5, and the 7 overwrites the 6).

In some apps however it works fine, for example in TextEdit or Firefox...

I probably just pushed some keyboard-shortcut which made this issue, but it really makes me go crazy. Could you please help me?

Thank you very much!
I was having the same problem with my HP SK-2028, and I found something that at least sort of works. If you turn on 'slow keys' in the accessibility settings and play with the settings a little bit, eventually there is a sweet spot where you will be able to type your numbers in, albeit a little slower, but at least it will function like it is supposed to. I found a spot in between the first two bars so I don't have to type tooooo much slower than I usually would. You can press alt+command+F5 to bring up the quick-accessibility options pane to quickly deselect or re-select slow keys as needed

-Amy