Are you able to share some more info like the Ansible version you are on, the task you are running. A 500 status code means internal error (internal to the http server) and usually indicates a problem on the remote end. You need to be able to debug what is happened in the times of a 500 error to determine what is happening, there is not much we can do from there.
I’m not sure, there is no difference between the first and second execution from an Ansible perspective, you are best off trying to replicate the issue reliably. Things to look for
Whether it is failing at a certain point in the day (is the server under load at this time)
Whether it is the same file
Whether this is happening on different sites
Whether this is happening on different Windows hosts
From there you can hopefully narrow down a set of circumstances that will allow you to replicate the issue reliably and then ultimately find the cause.