what did you put into the folder /docker/nc/nextcloud/php?
why not to put your additional config into
/docker/nc/nextcloud/php/nextcloud-uploadsize.ini
upload_max_filesize = 2048M
post_max_size = 2048M
max_execution_time = 200
memory_limit = 512M
...
and map only this file to the container
volumes:
- /docker/nc/nextcloud/php/nextcloud-uploadsize.ini:/usr/local/etc/php/conf.d/nextcloud-uploadsize.ini
- /docker/nc/nextcloud/html:/var/www/html
?