rc_joins rate limits dont function

[matrixbot]

This issue has been migrated from #16002.

---

Description

For test purposes i added this to my homeserver yaml:

rc_joins:
  local:
    per_second: 1000
    burst_count: 2000
  remote:
    per_second: 1000
    burst_count: 2000

but i still can just join 10 rooms and then get the rate limit error

Steps to reproduce

change config and try to join a bunch of rooms at once

Homeserver

my own

Synapse Version

1.88.0

Installation Method

Docker (matrixdotorg/synapse)

Database

Postgres 15

Workers

Single process

Platform

Docker

Configuration

see discription

Relevant log output

MatrixError: [429] Too Many Requests

Anything else that would be useful to know?

No response