Somtimes they honestly just use different packaging for the same product. I would suggest trying a store brand for awhile, not just one time, then if you're sure you just don't like it try a different one or go back to what you're used to. Your reader may have it in reverse. Lots of grocery store chains make the brand name products. My husbands chain owns its own bakery and dairy.
Main thing is to look for the cities where packaged.
If I see something from Cincinatti with a certain zipcode, I know my husband's company made it. If the store brand doesn't have the company HQ address, I look for the brand name and compare addresses. There's even a free weekly email newsletter. All rights reserved unless specifically noted. All advice should be weighed against your own abilities and circumstances and applied accordingly.