Detroit 60 12.7air conditioner

So my a/c cools great at a low rpm or idle and blows strong as it should but when I accelerate it still blows cool for the most part but it loses its blowing strength it's like I turned it down from 4 to the 2 setting, what could it be and where exactly do I need to look to possibly fix the problem. I know on a regular car or truck the vacuum check valve could be bad but I've looked for the diagram and I have no idea where that would be or what to even look for, any help would be greatly appreciated.

 

Well that makes sense, now that I think about it I'm no mechanic, any idea why the rpm's being higher driving down the road would make it do that?

 

2020 Coronado

 

Just sounds like something's closing off