Dagger is aflame but not sure why?

My rare (blue) Singular Purpose Dagger is permanently aflame but I can’t figure out why. It’s not a visual glitch either, it’s setting enemies aflame. It was infused with a blood gem that gives it 9 health on kill. The modifiers only say “Attack deals 11” “Gain 19” “Gain 9”, so i’m guessing there are words missing here and maybe one of these explains the flames?