Omen of homogenous exaltation didn't work

I was crafting some ES gloves, I had all suffixes filled and had only one prefix which was T1 % energy shield increase (defence tag). I used both omen of homogenous exaltation and omen of greater exaltation. Expected outcome should be to get 2 more prefixes with defence tag which should be another ES increases but what i get was flat fire and lightning damage. Was it a bug or did i miss something?

It is impossible for us to answer because you did not list the suffixes. But I assume you have either attack or elemental tags in the suffix