Welcome back to the Community, @redoaklandscape.
Since you already tried to delete the deposit and post the payment to the correct customer's account and the issue persists, I highly suggest contacting our Merchant Support team. They have tools such as screen-sharing (remote access) that can pull up your account in a secure environment and check the cause of this odd behavior. They're also able to perform other troubleshooting steps to fix this for you.
Refer to this article and proceed to the QuickBooks Desktop with Payments to get their most updated contact information: Contact Payments Support.
Just in case, I'll add this article for future reference: Automatically record QuickBooks Payments bank deposits.
Please let me know how it goes or if you have any other issues in the comment section below. I want to make sure everything is taken care of for you. I'm always here to help. Have a wonderful day!