When a monk puts on armor or equip a shield, they are suppose to lose unarmored defense and instead get the AC from the armor and shield if they are proficiency with it.
On the site, when armor or shield is equipped, it does remove Unarmored movement and Martial arts. However, they keep their unarmored defense AC.
If you have multiple methods of calculating AC - DNDBeyond chooses the one that gives you the best AC. So if your unarmoured defence is better than armour + shield - it'll keep the unarmoured defence and pretend you don't have armour on.
If you really want to lower your AC by wearing armour and a shield - you can always click on the AC shield on your character sheet and customise it.
When a monk puts on armor or equip a shield, they are suppose to lose unarmored defense and instead get the AC from the armor and shield if they are proficiency with it.
On the site, when armor or shield is equipped, it does remove Unarmored movement and Martial arts. However, they keep their unarmored defense AC.
If you have multiple methods of calculating AC - DNDBeyond chooses the one that gives you the best AC. So if your unarmoured defence is better than armour + shield - it'll keep the unarmoured defence and pretend you don't have armour on.
If you really want to lower your AC by wearing armour and a shield - you can always click on the AC shield on your character sheet and customise it.
Mega Yahtzee Thread:
Highest 41: brocker2001 (#11,285).
Yahtzee of 2's: Emmber (#36,161).
Lowest 9: JoeltheWalrus (#312), Emmber (#12,505) and Dertinus (#20,953).
Basically DDB coded a shortcut for picking an AC calculation not considering that players would choose to try to invalidate them.