Rejected ACH payments

I’ve recently tried paying an invoice online via ACH through a Quickbooks email link that was sent by a vendor of mine.

This link had two invoices attached so I proceeded to use my business bank account to pay both. One of the invoices went through and one was instantly rejected. I had the vendor resend a new link and tried paying multiple times - rejected every time. Tried waiting 24hrs as quickbooks suggested - still rejected. Vendor sent me a new link for a lesser amount and that one went through immediately. Tried paying remaining amount and that was rejected. Ended up paying with a credit card.

i called my bank and they see no attempts for any of the rejections only the ones that went through. I’ve also talked to the fraud department at my bank and they verified no rejected transactions from the bank.

Ive used other vendors ACH payments to pay payment without any problems for 26 years I’ve been in business. The amounts of the ACHs were substantially greater for most of these transactions.

Im very frustrated since this is a new vendor that I plan on doing a lot of business with and this should be a simple solution to make payments. 

Any suggestions?