Lots of broken stuff... not a single docker compose reference I found that worked. Been spending a day just trying to make nextcloud + mariadb work. (Edit for additional context: The official now unofficial documentation from Nextcloud is not functional and has caused the troubleshooting "adventure": https://github.com/nextcloud/docker/?tab=readme-ov-file#base-version---apache)

If anybody can share a working docker-compose file (with image tags), you'll be saving a soul. Otherwise, I can't be spending any more time on nextcloud :(

SOLVED: This is what worked for me after trying different versions and docker images.

Nextcloud: lscr.io/linuxserver/nextcloud:28.0.4 (the latest = v29 has breaking changes with mariadb and causes internal server error during installation)

MariaDB: lscr.io/linuxserver/mariadb:10.11.8

Here's the working docker compose file with nginx proxy manager. I use 4430:4434 for SSH reverse tunnel, but port 80 on localhost should be just fine

services:
  nginxproxymanager:
    image: 'docker.io/jc21/nginx-proxy-manager:2.11.3'
    container_name: nginxproxymanager
    restart: always
    environment:
      - TZ=Asia/Seoul
    ports:
      - '80:80'
      - '81:81'
      - '443:443'
    volumes:
      - ./data:/data
      - ./letsencrypt:/etc/letsencrypt


  nextcloud:
    image: lscr.io/linuxserver/nextcloud:28.0.4 # latest breaks
    container_name: nextcloud
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Asia/Seoul
    volumes:
      - ./nextcloud/config:/config
      - /path/to/data:/data
    ports:
      - 4430:443
    restart: always
    depends_on:
      - nextcloud-db


  nextcloud-db:
    image: lscr.io/linuxserver/mariadb:10.11.8 # pinned for sanity
    container_name: nextcloud-db
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Asia/Seoul
      - MYSQL_ROOT_PASSWORD=
      - MYSQL_DATABASE=
      - MYSQL_USER=
      - MYSQL_PASSWORD=
    volumes:
      - ./nextcloud-db/config:/config
    ports:
      - 3306:3306
    restart: always

TIP + DISCLAIMER: The All-in-One (AIO) installation and corresponding docker image is currently the OFFICIAL one. Read better... don't be like me. Others seem to find AIO's ballooning logs an issue (see comments) so use your own discretion.