Honestly, that's wild consistency. Tbh it reminds me of my buddy's pellet grill that would always die at 160 degrees no matter what he cooked. We spent a whole summer blaming his wood, his probes, even the weather before he found a tiny firmware bug. Ngl, have you checked if your thermometer is reading ambient temp right near that stall point?
Oh man, that's a solid point about checking the thermometer. But I'm pretty sure the stall itself is real, it's just the meat sweating and cooling itself. The weird part is how it always hits exactly 160, like a switch flips. That's what makes me think it's the grill's controller, not the meat.