I found the root case. I had renamed the container “standalone” but apparently something went wrong and even though Discourse worked, some bits and pieces were still looking for “app”.
After a docker restart and OS restart the forum was running, as “app”, even though the container was “standalone.yml”.
I have no idea how this could have happened, isn’t the container name just the yml file name?
Can I force the execution of the performance report or do I have to wait for cron to trigger it?