The more important problem with the SoJ’s new power is that it is basically useless.
95% or more of all builds are already focusing on only one element, which means that this ring will do nothing for most build, and also you have to give up a ring slot or a cube slot which could be used for a much, much better ring, like Unity, F&R, CoE, Compass Rose, etc.
The most simple fix for this ring would be to increase its [Single Element] Damage Bonus from 15-20% to 35-40% and maybe even the Elite Damage from 25-30% to 30-35%.
That would make it at least make it worth to equip it since the damage is now closer to the other rings.
It can be further improved by changing the legendary affix so that all your [Single Elemental] Damage Bonuses combine and you gain the accumulated damage to all elements (e.g. when you have 15% Fire Damage, 30% Cold Damage and 10% Poison Damage, you gain 55% Increased Damage to all Elements).
^^this is actually how I thought the ring would work when I first read the description of the new affix.