No preview images in google search results because of relative img src url?

Hello together,

running grav for a small project ( I am using a theme called hola.

While optimizing the content for a better google page ranking i recognized that i did not get a preview image in the google search results shown. Even if the image have a proper alt-text and is published on the website.

While reviewing a little bit the differences between pages where such an preview image is shown and the others i found that for every entry with a thumbnail shown on the page results the image source is given as full url instead of a relative path. On my grav instance all image urls are relative. Therefore i am reaching out to you to discuss on some questions

  1. Do you recognize the same? Is there anyone out there with a grav website which does show image thumbnails in the search results?

  2. Are you aware about a possibility to configure grav using the full urls instead of relative ones? Is there maybe a trick i can manipulate my own instance to test my assumption?

  3. Or do you think i am maybe on a complete wrong path and there is another reason why google does not show images for my website on the result page?