Proof failure : vimarsana.com

I am using Ken folkish 50% whole wheat bread, I am milling red hard winter wheat 500g, white flour 500g It all seems to go ok until the proofing. When put in proofing basket it seems like the right texture but When I take it from the proofing basket it’s seems soft and hard to handle running round my hands. Not cracking sound when I take it out even. Taste is good but would