HELP: High-Protein Whey Bread

So I've been trying to bake a sandwich bread with powdered (unflavored) whey protein and it's been going....poorly. I started with Sally's Baking Addiction sandwich bread recipe and added 50g of whey powder to it.

The dough ends up unbelievably sticky, with absolutely no structure whatsoever. After 10 minutes in the stand mixer, still can't pass the windowpane test. I even added 40g of vital gluten, still ended up crumbly with no structure whatsoever. All I can guess is that the protein is inhibiting gluten formation, but even adding additional gluten hasn't solved my problem so I'm hoping the wizards of dough can help me out here.

My recipe from my latest attempt:

  • 200ml water, warmed to about 110°F (43°C)
  • 60ml whole milk, warmed to about 110°F (43°C)
  • 5g Yeast 
  • 30g granulated sugar
  • 50g unsalted butter
  • 1 and 1/2 teaspoons salt
  • 430g bread flour
  • 50g Whey Protein
  • 40g Gluten

Do I need to do something like a Yudane or Tangzhong perhaps to get more gelatinized starch?