Space and Enter keys work only after frequent press?

On my Lenovo laptop, the blank, enter and delete keys work only after I press one of the keys about 30-50 times. The strange thing is, as soon as one of the buttons works, they all work. So it does not seem to be a hardware problem. After a restart and if the keys have not been used for a long time, you will not be able to react again until frequently. External keyboard works right away, but unfortunately is not an option for me…

Does anyone know the problem and has a solution?

Try to remove the buttons if that is intended. Then use moist water to clean the switch below the button. Maybe it will work then.