(FP) Avast blocks HTTP POST with zip in request body

Viruses and worms
1

I’m working on a website. The website at some point sends an ajax POST request containing a zip file in the body, on the same domain.

On a customer’s computer, that POST request is blocked by Avast (disabling Avast solves the issue).

What reasons could cause Avast to block a request? As a developer, which good practices should I follow to avoid the request to be blocked?

2

What does Avast say…? Post a screenshot.

3

Avast says nothing. We know it’s Avast because disabling it solves the issue.

Chrome says the request has been reset.

4

What part/shield of avast is blocking it ?