Weapon effect is not working on this Shield: "Font of Thunder Mirroed Spiked Shield"

The bug is in the title!

I've tried others effects too, but none of them have worked in this shield.

Screenshot of this shield with weapon effect:



https://prnt.sc/1gdvtbp

Same weapon effect with any other shield:



https://prnt.sc/1gdx3nq

I hope u fix it!