PayPal "Proceed to Payment" Button 304 Error

We have about a two year old build of Sharetribe that has been running on CentOS7 using PayPal Adaptive Payments where both us and our sellers have PayPal Business accounts. All had been working fine.

Now suddenly when a user clicks the “Proceed To Payment” button to initiate the PalPal payment the server starts returning a series of 304 errors non stop until you leave that page.

I am also getting this error when I look at the browser session “An error occurred during the payment process. Could not finalize your PayPal payment.”

I changed the Nginx conf file to not cache like:

location ~ ^/(jpeg|jpg|png|gif|bmp|ico|svg|css|js|json)$ {
    expires -1;
}

location ~* \.(?:manifest|appcache|html?|xml|json)$ {
    expires -1;
}

Still get the 304 error after trying to stop the caching to debug it.

Does anyone have any advice or suggestions for us to trouble shoot or solve this?

Some more information on this. When I click the Proceed to payment button here is what is happening and then in just keeps throwing the 304 errors until I leave that page:

200 POST json https://example.com/en/listings/1851/initiated?person_id=xzSN0v0QPa7T7tUiU1oljA

200 GET json https://example.com/en/transactions/transaction_op_status/5f38c464-4634-11eb-9c4b-5ee7d55a9a73

304 GET json https://example.com/en/transactions/transaction_op_status/5f38c464-4634-11eb-9c4b-5ee7d55a9a73
304 GET json https://example.com/en/transactions/transaction_op_status/5f38c464-4634-11eb-9c4b-5ee7d55a9a73
304 GET json https://example.com/en/transactions/transaction_op_status/5f38c464-4634-11eb-9c4b-5ee7d55a9a73
304 GET json https://example.com/en/transactions/transaction_op_status/5f38c464-4634-11eb-9c4b-5ee7d55a9a73