It's likely that the contact cleaner you used has oil in it to protect electronics from oxidation. However, this may be causing an issue in your buttons. First, the oil is likely lubricating the switch inside which keeps it from giving a 'clicky' feeling. Also, the oil is probably on the contact that registers a push, where it may be isolating the contact keeping it from registering a push. Cleaning your buttons with rubbing alcohol may dissolve and wash out the oil and help your problem.