Equipment not adjusting stats properly

On my character sheet I've noticed that the robe of the archmagi isn't properly adjusting my AC.It still has my AC at 13 and i'm not wearing any other armor. I do have a ring and some headgear (circlet/headband) but removing them doesn't fix it either. I'm also wearing the headband of intellect, it is equipped in my inventory but it doesn't alter my Int score.

I assume you are using the 5e OGL character sheet. The individual stats for the character (STR, DEX, CON, etc.) are not updated based on items in v1.6 of the character sheet. This will be changed in the upcoming version (v1.7) that should be released sometime next month (September 2017). I just did some checking with the robe of the archmagi and it turns out that the armor adjusting attribute  (AC +15) is most likely meant to be a custom AC formula rather than a direct adjustment. There are two things you can do: 1) Use the Custom AC setting on the settings page with the formula 15 + Dex + None 2) Change the AC +15 modifier of the item to AC +5. Apparently the real reason it is not adjusting is because the AC +N formula can only account for single digit numbers. You should have noticed that the robe, when equipped, was adjusting the ac of the character by 1.

Thanks. That was really helpful. For the robe I went with AC+5, just seemed easier. And when version 1.7 goes live is there anything we have to do in-game to update or it just automatically happens?

I believe that it will be automatically updated