Problems after update / migrate in docker

Hi,

I have the following Configuration:
Nextcloud in docker Container accessed over letsencrypt reverse Proxy (in docker)
Startetd with nextcloud version 19.0 and everything worked fine.
My docker-compose:

version: "2.1"
services:
  nextcloud:
    image: linuxserver/nextcloud:19.0.3-ls100
    container_name: nextcloud_19
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Europe/London
    volumes:
      - ./data/nextcloud/config:/config
      - ./data/nextcloud/data:/data
    depends_on:
      - mariadb
    restart: unless-stopped
  mariadb:
    image: linuxserver/mariadb
    container_name: mariadb_19
    environment:
      - PUID=1000
      - PGID=1000
      - MYSQL_ROOT_PASSWORD=SecPass4Nextcloud
      - MYSQL_DATABASE=nextcloud
      - TZ=Europe/London
    volumes:
      - ./data/mariadb:/config
    restart: unless-stopped
networks:
  default:
    external:
      name: dwi_letsencrypt

after a few Month I tryed to update the nextcloud over web Interface to 19.0.4
The update worked but after the update nextcloud was very very slow. Web Interface does not work most of the time (timeout)
Syncing with other devices also does not work.

I have tryed to delete the broteforce attempts with

select * from oc_bruteforce_attempts 
delete from oc_bruteforce_attempts

After that I try to setup a new nextcloud version in docker, this time a 19.0.3 (I could not found 19.0.4)
nextcloud started fine, all directorys are there.
Then I dumped the old database like that:

# Backup
docker exec mariadb /usr/bin/mysqldump -u root --password=xxx nextcloud > nc_backup.sql

in the new environment

DROP DATABASE nextcloud
CREATE DATABASE nextcloud

# Restore
cat nc_backup.sql | docker exec -i mariadb_19 /usr/bin/mysql -u root --password=xxx nextcloud

after that I linked the old user dirs into the new folder structure

ln -s /home/dirk/docker/nextcloud/data/nextcloud/data/dirk/ .

The new system started an everything looks OK but…

It was not possible to see photos in the web-view.
and what I found is that in the folder

./data/nextcloud/data for every user a subfolder and a folder mariadb

this is the structure ./data/nextcloud/data
  - alex
  - dirk
  - index.html
  - mariadb
      - alex
      - appdata_ocfy5nr3caa5
      - dirk
      - files_external
      - index.html
      - nc_adminIstrator
      - nextcloud.log
  - nextcloud.log

Now I have two questions:

  • what is the best way to update nextcloud in a docker environment?
  • what can I do to make nextcloud work again? (or what is the right way to migrate data to a different version)

Thanks in advance
Cheers
Dirk

[/details]

Nextcloud version 19.0.3:
Operating system and version Ubuntu 18.04:
Apache or nginx version runs in docker:
PHP version runs in docker: