Macbook pro 2011 Delete key doesn't work

I have recently purchased a used 2011 MacBook Pro 13" i5, it's in great shape but the volume keys and the delete key don't work as they should and it takes about 10 to 15 seconds for them to respond.

I never noticed the problem at first and since I am only using this for work; I boot camped the computer and noticed there was a problem on the windows side so thinking this was a windows installation issue, I started re installing drivers but sure enough I experience the exact same problem with these three keys on the Mac side as well.

my operating system is High Sierra set by the previous owner

any information would be appreciated. any idea as to why this is happening? and what I should do to fix it?