Canon R5 Mark II Auto Tone issues

I just did a huge camera upgrade this past week from a 5D Mark IV with the old Mark I EF 100-400L to a brand new R5 Mark II and the RF 100-500L lens. I do mainly aviation/airshow stuff. 

I often start my edits in LRC by just seeing what the auto tone suggests, it’s usually been pretty close on RAWs from the 5D IV. With the new camera it’s been very hit or miss, often drastically over or underexposing the images, clipping the blacks and highlights etc. Am I missing something here that I need to configure in LRC? Is it somehow expecting my old camera and applying the algorithm as if it’s that or something?

Thanks, appreciate any help - definitely still just scratching the surface on learning the R5 II, I know things have changed pretty drastically with these mirrorless cameras vs. what I’m used to so it may be something I’m doing wrong.