I have made a homebrew item which, once equipped, sets the wearers AC to a certain number using the "Set" modifier, but when I equip it to a character, it does not work. Can someone look into this?

Here is the item: https://www.dndbeyond.com/magic-items/4567061-the-armor-of-the-battle-angel

Here is a character that currently has it equipped: https://www.dndbeyond.com/profile/Princedg5678/characters/51452234

Quote from Stormknight >>

I don't believe that modifier functions for magic items in the way you're expecting. It could also be a problem with trying to set armor class to 50 being too high a value.

 Thanks for the insight. I did check to see if 50 was to high of an AC that the sheet could handle (using the override score customization), and it can handle it. I will have a look at it, thanks! If you have any idea of what to do, that would be appreciated!

1. Does the item require Attunement? If so…. 
2. Did you template it from an item that did, and then remove that requirement? If so, you will have to recreate it from scratch due to a known glitch.

Quote from IamSposta >>

1. Does the item require Attunement? If so…. 
2. Did you template it from an item that did, and then remove that requirement? If so, you will have to recreate it from scratch due to a known glitch.

 no, it did not require attunement at all