Using IIS 10 on Windows Server 2019. I am not a server admin, I am a developer who manages sites on the rented server.
I have a report that runs through names, and via a client side scripts, access an ajax file to check if the person's status is valid. So, when the page loads, ~100 ajax calls could be run. On some servers, this report seems to complete perfectly (with 100 names checked), but on the current server - after a few successful calls, the rest (like 90% of them) are rejects with a generic 403 error - 403 Forbidden.
When I run each of these individual links manually - they load perfectly. Maybe its some kind of a traffic block - when a high number (100) of requests to the same file (with different parameters) are sent - that some are blocked?
Where would I be able to check this?
Not sure if this is related, but on the odd case it might be - I'll mention it: on Chrome, sometimes all css/js files linked in the header of the site, are rejected with the same 403 error. Which obviously messes the site. on Firefox, there is no similar issue, even the same exact pages.
Thanks
UPDATE: Uploading what seems to come up in the Trace. the substatus of 501 does not seem very telling?
![enter image description here](https://i.stack.imgur.com/snrXU.jpg)