I'm trying to recreate a higher level character in DNDBeyond, but can't seem to select the feat variant option for my 12th level ABSI. When I do, I get a pick list that includes only two feats--Grappler and Snirv... Magic (I'm a human paladin). All other feats are missing, including the one I want (shield master). What's up?

D&D Beyond can be used for free and contains information from the following "free to use" sources published by Wizards of the Coast:  D&D 5th edition SRD , D&D 5th edition Basic Rules and Elemental Evil Companion.

Content from other sources, such as the Player's Handbook, Dungeon Master's Guide or Monster Manual will need to be purchased from the Marketplace, or accessed via another user sharing content with you via their Master Tier Subscription.

You will have to purchase the PHB to access the other feats as only content in the SRD is included for free.

Or you can just purchase the feats package or even just the feat that you need if you dont want to buy the entire thing.

Hmmm. But this is in a campaign for which the DM the total package...

Make sure the owner of the Master Tier subscription has enabled the sharing, and that you are creating the character inside the campaign.