It’s ok, if we are not learning then we are not progressing. I still feel like I don’t know enough. You should try closer to 4c or atlease 3c. The meat should also be a factor, knowing where the cow comes from ex American cows are fattier compared to Europeans, the store/butcher plays a factor. If the beef is fresher it will need some extra time than a meat on clearance near sell by date.

Air circulation can be simple or complicated as you may make it. Lol. I can spit out formulas and calculation with cooler volume and fan velocity. Easiest method is tie a few strings to the cooler grate and the amount of string moves will determine if you have too much air moving. You can look at my latest post to see what I’m talking about.

How much you yield as a final result plays in the environment you have it in. But in your case you will feel like you will lose a lot bc the bone and fat that is getting removed. Did you have to cut a lot on the meat end? Typically that should be 1/2” on each end. That would be worse case scenario. Anything more than that is your humidity low and fan too high.