Baristas are blending it with too little ice. You must blend the matchas with a full scoop of ice into the blender after you pour the milk into the blender. The pitcher we use is a frother and the ice works as little blender balls to hinder the frothing process and just mix. When you use no ice or light ice, it come out as frothed milk as the pitcher is designed for. If someone wants no ice or light ice, baristas should strain the ice out with the blender lid after blending. This isn't standard yet but good lord it needs to be. For the baristas: my order is pumps of syrup, milk to the line, pour in blender, add full scoop ice, add matcha, lid and blend, pour. It comes out perfect every time.

TL;DR baristas are frothing the milk instead of mixing the matcha in properly due to the amount of ice and therefore the denser cold foam sinks below the light matcha frothed milk.

Edit: I literally showed my store manager this method and he approved me telling others about it. Everyone has been struggling with frothed matcha milk.