For monk, WIS bonus isn't removed when I add a Shield?

For testing, I gave my Monk a Shield; their AC went from 16 to 18, but I think it should be 15. (10 base + 3 DEX + 2 from Shield)

Yeah, DDB doesn't currently disallow armor class calculations like Unarmed Defense, Dragon Hide, etc. when it should.

But you'll find that your Monk correctly loses the Martial Arts benefit to attacks when wearing an armor or donning a shield.

It looks like Speed isn't impacted by donning a shield either. I'm guessing this is due to how things are coded in regards to shields.