Possible Bug with two "Curse on Hit" rings

I have the following problem, I have only one curse limit and a corrupted ring with a great implicit and "Despair on Hit" suffix, but I want to use it in a fire build, with another ring with "Flammability on Hit".
I've tested both rings in various ways and despair always applies.
At first I thought it might be a ring slot priority, but I tried toggling rings, and just kept applying despair.
So I thought it might be an alphabetical priority, but I tested the ring with "Despair on Hit" along with a ring with "Conductivity on Hit", and also Despair is the one applied again.
I also tested it with rings with and without influence, and got the same result.
Is there any logic the game should follow in this case of having two rings with different "Curse on Hit" suffixes? Maybe it's a bug? I don't know...
Below images of the rings and the test.

Edit.