Bitnami (Moodle) container won't run on M1: "Couldn't create the mpm-accept mutex"

I want to run a Bitnami container on Apple M1. My question is about Bitnami Moodle, however, I suspect my problem to be rather general as it occurs when starting Apache.

error message:

(95)Operation not supported: AH00023: Couldn't create the mpm-accept mutex

I added platform: linux/amd64 and added a Dockerfile:

from docker-compose.yml

moodle:
  platform: linux/amd64
  build:
    context: .
    dockerfile: ./Dockerfile
  image: bitnami/moodle:4

Dockerfile (see this source):

FROM bitnami/moodle
RUN echo 'Mutex posixsem' >>/opt/bitnami/apache2/conf/httpd.conf

I also tried adding the --platform argument when building: docker build --no-cache --platform=linux/amd64 .

None of this helps. I can see relevant output when running docker build . ([2/3] RUN echo 'Mutex posixsem' ...), but I keep getting the same error when running docker-compose up.

Is there anything else I could try?