Thanks for reaching back out, @Jessiew3st.
I want to ensure that your payments concern gets taken care of. Let me point you over in the right direction who can provide clarifications with this matter.
In situations like this, It'd be best to reach out directly to our Merchant Services Department. This team is the best resource for such inquiries as they are able to pull up your account securely while the Community is a public forum. Once they gathered your information, they'll discuss with you further the reason why your customer's payments are on hold.
Additionally, here are some references that you can check out about handling payment holds in QuickBooks for your future use:
Please know that I'm just a reply away if you have any other questions about concerning payments. I'm always ready to help. Take care!