Invalid or missing timestamp in JWS request

Just yesterday we started having customers tell us we had this issue.

I searched Google for an answer to this and I found the following article: https://simplify.desk.com/customer/portal/articles/2085428-invalid-or-missing-timestamp-in-jws-request-message

I don’t know how to change a server timestamp, and I don’t know how to find out what the timestamp should be from the payment Simplify.com?

I already put the website in Support Access Mode.