Sorry if this is a repeat, but it's something I noticed.

When making a Levistus Tiefling there's an inconsistency in which Ability Scores (among other things) get modified by being that kind of Tiefling vs a regular Tiefling

In the character builder it states

Racial Traits
+2 Charisma, +1 Intelligence, Darkvision, Hellish Resistance, Infernal Legacy

However, in the details page it states

Ability Score Increase

Your Charisma score increases by 2, and your Constitution score increases by 1.

On the character sheet itself it follows the Details Page instead of the Character Builder summary. It's confusing, because then you don't know which one to actually follow. There's also the issue of Armor of Agathys being a Warlock-only spell, and so because of that even though it's part of official content it doesn't show up on the character sheet as it should and you have to find a workaround to make it show up.

The +1 INT and infernal legacy racial traits belong to the base Tiefling. Variant races (such as Levistus Tiefling) show the base races traits in their summary, but have the correct traits in their details.

The Levistus Tiefling is working correctly. It gets +1 CON instead of INT, and it gets all 3 of its spells from legacy of stygia at the right level.

Armor of agathys is a spell from the PHB, your character will not have access to it unless you have bought the book, the spell, or have ot shared to you in a campaign. 

I understand it's working correctly, but the way it's written is confusing and inconsistent in the builder. 

As for the Armor of Agathys, I bought that content and own it. It doesn't show up but my character is a Wizard instead of a Warlock. I even tried making a brand new character and it isn’t there. I have to write it in myself. 

Is your character 3rd level?

Can you post a link to your character sheet?

Quote from Grimsingingmaid >>

I understand it's working correctly, but the way it's written is confusing and inconsistent in the builder. 

As for the Armor of Agathys, I bought that content and own it. It doesn't show up but my character is a Wizard instead of a Warlock. I even tried making a brand new character and it isn’t there. I have to write it in myself. 

It is consistent with the way variant races are displayed on DDB (that is to say: incorrectly in summary, but correctly in detail). Variant races show the base race's summary no matter how different the variant is. Hopefully it gets fixed in next builder update.

You didn't get armor of agathys at level 3 as a 2nd level spell? Because I tested it with a level 3 fighter and it was there.

I have two versions of the character, a level 8 as a backup in case my actual character is killed, and a level 10 for a one-shot we're doing for my DM's birthday. Neither of them have the spell, and I even made a rando character at the appropriate level and it still didn't show up anywhere.

Here she is at level 8 without me adding it as a custom feature like I did for the level 10.

https://www.dndbeyond.com/profile/Grimsingingmaid/characters/7585207

Is it because she's a Wizard and it isn't a Wizard spell? Legacy of Stygia shows up under Features & Traits just fine, and it's included in the list, it's just not included as something I can tick off as 'hey I did it', or as a 2nd level spell in my spell list.

Just to be sure:

1. You own either the PHB or specifically armor of agathys on DDB.
2. You own the Levistus Tiefling and this is not a homebrew copy of it.

Because I made a level 3 wizard and it had the spell, I can't reproduce your problem.

You may need to make a support ticket: https://dndbeyond.zendesk.com/hc/en-us/requests/new?ticket_form_id=602788