GitLab CI FTP deploy with mwienk/docker-lftp docker image

.gitlab-ci.yml

stages:
  - test
  - deploy

cache:
  paths:
    - vendor

# test job
test:
  stage: test
  image: edbizarro/gitlab-ci-pipeline-php:7.1
  script:
    - sudo composer install --prefer-dist --no-ansi --no-interaction --no-progress --no-scripts
    - vendor/bin/phpunit --configuration phpunit.xml

# upload job, see https://lftp.yar.ru/lftp-man.html
upload:
  stage: deploy
  image: mwienk/docker-lftp:latest
  script:
    - lftp -e "set ftp:ssl-allow false; mirror -eRnv app web/app; exit;" -u $FTP_USERNAME,$FTP_PASSWORD $FTP_HOST
  only:
    - master
  when: on_success

I am getting "mirror: Address not available" although the same command works when manually entered... I am unable to find any information on that error. Any clue?

EDIT: it seems to be a DNS issue with the mwienk/docker-lftp:latest probably, because with IP instead of hostname it works?

I know this is old, but I had some troubles with mirror command. Because some FTP servers are not keeping the modify time from the source. But changing it to upload time. I was dealing with it by using another tool (FTP Deployment) to handle changes and LFTP just to do parallel upload.
If you are interested, I wrote an article about it here: https://dev.to/arxeiss/parallel-incremental-ftp-deploy-in-ci-pipeline-2511