Thank you for performing the suggested steps, MikeBox!

You should be able to select customers in the Customer drop-down when creating a purchase order. Since it gives you the same result, it'd be best to reach out to our Support Team for further investigation.

1. Click the (?) Help icon and enter Talk to a human (then type it again when prompted).
2. When asked by the bot, enter "Missing customer in the Customer drop-down".
3. Select I still need a human, then proceed with Contact us or Get help from a human.
4. Choose either Chat or Callback.

If you need more references on how to use a purchase order, please check these links:

• Create and send purchase orders in QuickBooks Online

• Add purchase orders to expenses, bills, or checks in QuickBooks Online

I'm looking forward to assisting you again. Take care!