Hello @secretaryHOA,
As of the moment, there isn't an integrated way to combine checks with the same transaction number. With this, you'll have to select both of your checks when creating a deposit to enter them as a single item.
Additionally, I've got you this reference for a compilation of articles you can use while working with us: QuickBooks Desktop for Mac - Vendors and Expenses.
If there's anything else that I can help you with, please let me know by leaving any comments below. I'll be here to lend a hand.