my omen of whittling wants to remove the wrong modifier

i have a +5 of all chaos spells wich is t5 and i also got 25% atribute requirement on it wich is t3 and i want to remove the t3 but the omen highlights the +5 of all chaos spells is this intended am i doing something wrong or might it be a visual bug either way i am a little too afraid to try because i dont want to loose the +5 of all chaos spells