Upgraded Mythic Helm for Sorc

I'm assuming this must be a bug, but our helm stats didn't change much.

+7 dex, +14 int, +124 armor... that's it. The other two got bigger increase, specifically in the dmg department. Rogue has 6 damage, warrior has 6.1 damage, but sorc stays at 2.8 damage?

Sorc had the worst helm to begin with, now the upgraded ones are WAY worse than the other classes upgrades.

So the other helms now add more than double what mage helm adds? and thats after myth bow was upgraded while myth gun wasnt

I really hope this is just a bug and nothing more.. upsetting to upgrade a myth helm make it untradeable and see that tiny change in stats.