The hidden Trump voter is people who are embarrassed to vote for him or are scared of the repurcussions of saying so. I am not surprised that the hidden vote is women.
There are cookie polls like this all over the Rust Belt, in PA, WI and MN, showing Trump beating Biden 2-1 at worst, a complete inverse of 2016. Women will lie to pollsters and others, but they will go to their favorite bakery in the area (or order it online which is even better for their privacy like a voting booth), see a cookie poll, and feel comfortable with buying the Trump one. That is something Baris unfortunately can't account for: natural behavior over being interrogated about your vote by a pollster.
This could also mean that the Biden woman vote is demoralized. Dunno. We shall see.