Failure to playback videos when sharing due to mixed content http/https with firefox

When sharing a video file (eg. mp4) via public link Firefox doesn't allow video playback when owncloud-docker is behind a https-reverse-proxy because it seems the page tries to load the video via a http://-URL

I don't see a switch to fix that via docker-compose.yml nor .env-File.

Exposing a http-service to the internet is not an option.

Any ideas?

