When eZ Platform is running on a custom port (ex: 8000), and the image_host setting (introduced in https://jira.ez.no/browse/EZP-29466) is used, the custom port is added to the URIs obtained from ImageVariation objects returned by the VariationHandler

ezpublish:
  system:
    default:
      image_host: 'https://example.com'

Example URI: "https://example.com:8000/var/site/storage/images/_aliases/small/9/8/1/0/189-1-eng-GB/Capture d’écran 2019-03-07 à 00.50.42.png"

Even worse, if a trailing / is added to image_host, the port number is added after the /:

"https://example.com/:8000/var/site/storage/images/_aliases/small/9/8/1/0/189-1-eng-GB/Capture d’écran 2019-03-07 à 00.50.42.png"