Well, I had simply presumed it was the same but they just changed the packaging. What I've shot is the picture on the top (the gold box). Despite being marked .223, it has crimped primers and annealed brass, which implies a military load.

I found the compare video I suspect you were referencing. Interesting that the 5.56 boxed ammo has a higher charge weight than the .223, but I also noticed the headstamp on the brass changed. If they changed brass they'd have to recalibrate the charge. The video I watch (Buffman) he got overlapping performance and concluded it's the same ammo.

I suspect they've just updated their recipe, but it's good that you pointed out that difference as I'd want to separate the brass between the two as I suspect you'd have to adjust accordingly. Would be interesting to check the case capacity of each to check that hypothesis, though.