A magnet wont stick to true stainless steel unless it's ferritic. A true Stainless Steel is also notoriously hard to keep looking clean and has different downfalls and upsides to it depending on the grade. There is several different grades of it that improve one thing or the next so it's no surprise that a different composition is being used and that a magnet would stick to it. Doesn't necessarily mean it's a bad thing though.

Found this

Most stainless cookware is an 18/10 grade (18 percent
chromium/10 percent nickel). The material difference between a 304 and
316 pot is negligible. However, the less common 316 grade contains a
small percentage of molybdenum ( Mo) and/or titanium (Ti). This makes it
more pricy and more corrosion resistant.

And a quick google showed that glad uses a 304 grade stainless steel that would most likely be non magnetic, however, another querry showed that they tend to use an aluminum or copper core in their cookware which would explain things, they use this for even heating purposes. Also depending on the process some stainless steel can be "ferritic". with magnetic properties and technically be classified as true stainless steel. I'd imagine the 316 grade would be somewhat magnetic too due to the amount of titanium and molybdenum in it.