I'm building my town with guards on 1.16.5, and I equip Guards with armor and shields from Epic Knights mod.
Sometimes, when i'm not nearby, shields used by guards stop rendering (but they are equipped back, when I open the equipment menu), then disappear completely. Maybe this is an issue on Epic Knights side, because the vanilla shield is working just fine.
I just wanted to notice that, and I hope I made myself clear.

I guess this bug is fixed in Epic Knights latest update, so, fine, I guess.