Best in bags claims it is better to not equip rings

In the following snapshot, best in bags claims that it is better to leave a ring slot empty than to equip a ilvl 316 Circle of Ascended Frost on a frost mage:
2a05e6525e4d472daac022958d876cd9

I’m not sure why that’s happening… thanks for the snapshot, we’ll try it out on our test server and see what’s up.