The label system they have had is certainly inaccurate quite often. My Walmart used to offer to reduce scanned prices to shelf prices, but don’t do this much anymore. This article also tells me that they can now raise prices a LOT quicker than you can ever determine if it is “justified”.
You’re lucky if the item is in the vicinity of the tag and you can figure out whether FN MSP D is the item you have in your hand. The local Walmart also got rid of the scanners in the aisle so you can check the price.