Order not processing in backend, but processing with gateway (Unique Constraint Violation Found)

New Magento 2 Install. Authorize.net and Paypal having the same issue.

Order is placed on our website
Payment is captured and accepted
The order DOES NOT show up in Magento`s backend.
Customer does not receive any confirmation emails

Making big problems for us at the moment. I tested it myself, and after it processed the credit card through authorize.net and captured the payment. I had a brief error that said, “Unique Constraint Violation Found”. Then went away and stayed on the checkout page.

We need these orders to process in magento back it’s like it’s not poling the data into the order form?

Not even sure where to look for this, or begin to fix it, there’s no real supported threads answering this question, can anyone offer guidance?

-Justin

UPDATE: When credit card used with authorize.net it will allow me to authorize/capture or void the card, however when paid with paypal, it will be stuck on authorization/pending as if it’s waiting for information from magento store. Please advise