Why is my keyboard not functioning like it should

Hi i have several accounts on my iMac

i noticed on my main account i had to hold down on a key for it to type anything.

so i started a new account and the same thing has happened after like 6 days.

can someone explain this?

where is the problem coming from?

i am not experiencing this right now for typing this as i am using another account. but please help. thank you.