Docker Compose Unknown Error on upload

I have a docker-compose.yaml:

volumes:
nextcloud-data:
nextcloud-postgres:

services:
postgres:
# Image tag (replace with yours)
image: postgres:13
volumes:
- /opt/dockerres/postgres:/var/lib/postgresql/data
environment:
# Database name (replace with yours)
POSTGRES_DB: nextclouddb
# Database user (replace with yours)
POSTGRES_USER: nextclouddbuser
# Database password (replace with yours)
POSTGRES_PASSWORD: YOU SHOULD NOT EXPOSE SENSITIVE DATE TO THE INTERNET (JK)
healthcheck:
test: [“CMD-SHELL”, “pg_isready -U $$POSTGRES_USER -d $$POSTGRES_DB”]
interval: 10s
timeout: 5s
retries: 3
start_period: 60s
restart: unless-stopped

nextcloud:
# Image tag (replace with yours)
image: nextcloud
volumes:
- /opt/dockerres/nextcloud:/var/www/html
ports:
- 8180:80

environment:
POSTGRES_HOST: postgres
DB_PORT: 5432
# Database name (replace with yours)
POSTGRES_DB: nextclouddb
# Database user (replace with yours)
POSTGRES_USER: nextclouddbuser
# Database password (replace with yours)
POSTGRES_PASSWORD: YOU SHOULD NOT EXPOSE SENSITIVE DATE TO THE INTERNET (JK)
# Nextcloud user (replace with yours)
NEXTCLOUD_ADMIN_USER: nextcloudadmin
# Nextcloud password (replace with yours)
NEXTCLOUD_ADMIN_PASSWORD: YOU SHOULD NOT EXPOSE SENSITIVE DATE TO THE INTERNET (JK)
# Nextcloud URL (replace with yours)
NEXTCLOUD_TRUSTED_DOMAINS: YOU SHOULD NOT EXPOSE SENSITIVE DATE TO THE INTERNET (JK).myfritz.net,YOU SHOULD NOT EXPOSE SENSITIVE DATE TO THE INTERNET (JK).myfritz.net,192.YOU SHOULD NOT EXPOSE SENSITIVE DATE TO THE INTERNET (JK)

healthcheck:
  test: ["CMD", "curl", "-f", "http://localhost:80/"]
  interval: 10s
  timeout: 5s
  retries: 3
  start_period: 90s
restart: unless-stopped
depends_on:
  postgres:
    condition: service_healthy

Nextcloud works but when i upload a file a get “Unknown Error”

Docker Logs:

127.0.0.1 - - [29/Sep/2023:13:08:38 +0000] “GET / HTTP/1.1” 302 1658 “-” “curl/7.74.0”
127.0.0.1 - - [29/Sep/2023:13:08:48 +0000] “GET / HTTP/1.1” 302 1664 “-” “curl/7.74.0”
176.199.99.208 - - [29/Sep/2023:13:08:56 +0000] “GET /apps/files/api/v1/stats HTTP/1.0” 200 953 “-” “Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0”
127.0.0.1 - - [29/Sep/2023:13:08:58 +0000] “GET / HTTP/1.1” 302 1658 “-” “curl/7.74.0”
176.199.99.208 - - [29/Sep/2023:13:08:59 +0000] “GET /ocs/v2.php/apps/notifications/api/v2/notifications HTTP/1.0” 304 783 “-” “Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0”
127.0.0.1 - - [29/Sep/2023:13:09:09 +0000] “GET / HTTP/1.1” 302 1658 “-” “curl/7.74.0”
176.199.99.208 - - [29/Sep/2023:13:09:12 +0000] “PUT /ocs/v2.php/apps/user_status/api/v1/heartbeat?format=json HTTP/1.0” 200 945 “-” “Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0”
176.199.99.208 - - [29/Sep/2023:13:09:15 +0000] “MKCOL /remote.php/dav/uploads/nextcloudadmin/web-file-upload-e65c9cde8df69ec8a34d5215af6c2a78-1696000155000 HTTP/1.0” 201 624 “-” “Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0”
176.199.99.208 - - [29/Sep/2023:13:09:16 +0000] “DELETE /remote.php/dav/uploads/nextcloudadmin/web-file-upload-e65c9cde8df69ec8a34d5215af6c2a78-1696000155000 HTTP/1.0” 204 568 “-” “Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0”
127.0.0.1 - - [29/Sep/2023:13:09:19 +0000] “GET / HTTP/1.1” 302 1662 “-” “curl/7.74.0”

As you see no error in Logs… Have anyone a idea what i could be?

Check your permissions and ownership on the filesystem for this directory. Looks like a place not accessible to user www-data

I have found it. Behind nextcloud i have as reverse proxy nginx which i.have configure to take bigger Attachments