Baby screaming

Hi girls!

Just looking for advice based on the experience for a situation I’m in that’s making me lose my mind. I’m a nanny to a little 9 month old boy, sweetheart, and such an easy baby. The family is amazing too. I thought I hit a family/kid jackpot two months ago when.. He started uncontrollably screaming. Now you may think he’s upset, crying and screaming along. No! He is absolutely happy, checking toys out or playing with kids when suddenly he bursts this extremely high pitched scream, similar to a horror movie one. I’m not even kidding. I keep thinking, how can a 9 month old have such loud voice. But he does. I am with him for 10h/day and needless to say I feel I’m losing my sanity. I tried everything, distraction, reading, singing, walking. Works for a second then he does it again. I was saying firmer NOs too, but I think that’s the least he understands at this age. The parents are aware of the situation, also witnessed it at times. They are both doctors though with crazy busy lives and I don’t think they understand the severity of the situation or what I’m going through. Today we were asked to leave the children’s library because the librarian said he was too loud to be there. And the looks I get from people is what I hate the most. Today, I thought about telling them I need a break of one day a week maybe to get through this phase if that is what it is. But then, dad’s dad, child’s grandpa, had a heart attack. And of course, it is definitely not the right time to ask for something like this at the moment they need me the most. Help! 😪🙁🤯🤕😭🤧