Does Keycloak throttle client-connections in any way?

Is there some internal mechanism which prevents Keycloak to be DOSed? I’ve read some old post from 2016 where somebody states that it is not.

I’m asking because i build an application making group memberships for users via the REST-API. This is doing some hundred calls in a row and suddenly the connection is broke. When i put a short sleep (1s) between 500-600 calls it continues to work. This looks like there are some throttlings active?

Maybe you’ve turned ON the Brute Force Detection: Server Administration Guide

Thanks, but i don’t think so, because this would end up in disabled user-accounts, right? Which is not the case.