To link Vimeo videos to the video portal, the direct download link to the video file must be used. See also: https://vimeo.zendesk.com/hc/en-us/articles/224823567-Direct-links-to-video-files
For further information and in case of open questions in this regard, we refer directly to the Vimeo support. Thank you for your understanding.
If there are any problems with Vimeo videos, we recommend Dropbox as an alternative cloud storage, as experience shows that this provider works best with our video portal. See also: Video portal explained