I’ve had the same exact experience at Walmarts in NC. I even took photos of the shelf prices. At first they would perform adjustments; later they acted like they I was the problem.
I even told them how particular items had been incorrectly priced for months. They did nothing and the shelf prices remained incorrect, so i stopped buying those items from them. All I wanted was to be told the truth while shopping the items.
If it happened in your state and mine, it doesn’t sound like a coincidence. Other people have had the same problem. It sounds like Walmart is hoping the customers won’t notice the higher price ringing up.