The container holds /etc/postgres files locally. After an docker-compose down the current state of these files is lost. The subdir 'conf.d' does not exist, which is referenced in the postgres.conf file. Also other files are missing.
As a workaround you can move the data directory out of the way, create a new data/data and restart the container. The container will rebuild a new postges configuration. Then stop the container, reset the data directory to the one with the real data und restart the container with docker-compose start