Thank you for the feedback. We don't show default categories on My Transactions page since they won't be in any of your transactions since when you create a transaction with a default category, we move that to your existing categories. We've added to our todo list the ability to see default categories when creating a new transaction or multiple transactions.
I have used both existing and created categories. When I go to the dropdown or url in my transactions or multiple transactions, not all of them appear. Is there a way I can make them all appear?