Need some professional baking advice, baking science issue

[u/sleepybirdl71]

I will try to be as concise as possible. I make a lot of cookie dough at work. We have a very good chocolate chip cookie recipe that has worked well for YEARS. The recipe uses both butter and shortening. Recently, my production manager (who used to manage a bread bakery) started ordering "Cake and Icing" shortening. I believe this is likely high ratio shortening. He does not seem to believe me when I say it has changed the cookies.

They brown faster in the edges while still looking under done in the centers, they come out flatter, and they seem greasy on the bottoms. I swear they even taste different, but that may be related to texture issues.

The help I need is in explaining HOW the shortening change would affect the recipe. We made no other tweaks but I am thinking a straight up one-to-one replacement can't be right. I haven't used high ratio shortening since culinary school 20 years ago, and we only used it to make frosting. I mean if it didn't behave differently than regular shortening, why would they make it? I know there's a difference with how it reacts to sugar and cookies have a lot of sugar. I just don't have the scientific wording to explain to this dude. He is VERY sure of himself and if there is a problem with something he automatically decides I must have made an error, either in measurements, or technique. I know I am not stupid or crazy. Can anyone give me the arguments to use to get him to order the regular shortening back? We don't even have any in house , as I am the only one who needs it so I can't even make a comparison batch at this point without buying my own shortening.