It’s a defective tube. I’ve seen a fair number of them, not restricted to any one brand. These flats can be hard to find because they start with a small break, but quickly deteriorate until the tube loses air quickly. If it happens with a new tube, you can be sure it’s a defect.
What do you do? Complain? I’ve contacted the distributor and both times I received free tubes. I’m not recommending you do this all the time. My reason for contacting the distributor is not so I can get my money’s worth, but to let them know there’s a problem.
I never saw flats like this until about five years ago. Now I see them occasionally. Molding a brass stem into a butyl tube is a complex thermal and contamination problem. I suspect it’s a flawed process. Who knows?
Just be aware of it and always carry a spare tube, or two.