Ancient desecration + omen of abyssal echoes roll low tier mods

Pre-conditions
Essence of the Abyss + Preserved Rib + Omen of Abyssal Echoes

Long story short: I had ancient desecration on the body and used omen of abyssal echoes. The first try gave me a T3 flat evasion (that's expected). Hopefully, to achieve t1-t2 flat evasion while having the Omen of Abyssal Echoes active, I rerolled and it gave me t7 flat evasion, which I had expected to be no less than t6. If it’s not a bug, it makes the omen of abyssal echoes useless.