How to Make Casein Protein Less Thick and More Drinkable in Shakes

Evening all. I've recently started incorporating casein protein into my nighttime routine for that slow-release goodness. The only problem is, it's like trying to drink mud. Seriously, it's so thick it feels like I'm eating a paste, not drinking a shake.

I've tried adding more water or milk, but then the flavour gets super diluted, and it's still pretty gloopy. I've also tried different shakers, even a blender, but the consistency is just... challenging. My current brand is Optimum Nutrition Gold Standard Casein, which tastes decent, but the texture is a killer.

Any tips or tricks from you experienced casein users on how to make it more palatable and drinkable? Should I mix it with something else? Does timing or temperature of the liquid make a difference? I'm open to all suggestions, because right now, it's a chore to get down.