Gear with wrong stats?

I have been seeing this a lot, not just on my gear but on the trade market. Not sure if its lack of understanding on my part, or a bug or something.

For example my current weapon has:
17% increased burning damage

And when I view advance descriptions:
17(26-30)% increased burning damage

So why is that showing less then the minimum it can have?

Some items could be legacy. When they make new changes sometimes they leave the old items as is. Some can be updated with divine orbs if buffed normally, but not always.

Like the old asenath gloves do not have explode, the new ones do. If you divine those they will not get the new mods.