Start typing characters in the drop-down, and the Accounts will populate the list.
Though my Tutorial for Expenses is originally based on the the Tutorial you mention, I didn’t like the way it operated, for the same reason that you are experiencing. Instead, I went about it a different way…
Search for Expenses and Payouts … you will find 2 different methods: Method Q (mine) and Method K (@Jesse). The approaches are similar, but differ slightly in the way Expenses are entered.