if you don’t get anything, please try that:
if that doesn’t help, please post:
Nextcloud-Version
Collaboraplugin-Version
error message
does https://collabora-domain/hosting/discovery show an xml File
docker ps
docker logs
result of docker info
anonymized docker start command
the anonymized content of their collabora-webinstance (f.e. /etc/apache/sites-enabled/collabora.domain.tld.conf)
which SSL-Certs are being used (self signed or from a recognized authority)
result of “uname -a”
the date of the download of the collabora-image
If it already worked or not and if possible with which image-date.