I am trying to categorize two different bank transactions in the same deposit download (one is an 'Add' and one is a 'Match'. I can't seem to do both (even in a split).

Let me provide you with the information, Bob-bikedurham-o.

When you split a transaction, you can only add it. Once you're done categorizing it, you can now click Apply and accept. 

You may want to exclude the transaction and deposit it manually instead. From there, you can categorize the transaction properly. 

Let us know if you have other concerns. We'll be around to assist you. Take care!