Hello rjvs,
Thank you for contacting WP Travel Engine team!
One possible reason for the problem you’re experiencing could be the failure of thumbnail generation on your website. You can try resolving the issue by regenerating the images to confirm this. This can be done by installing and activating the Regenerate Thumbnails plugin.
After activating the plugin, you need to regenerate the thumbnail via Admin Dashboard > Tools > Regenerate Thumbnails.
Additionally, it is possible that the issue arises from the fact that the values for Image Sizes under the Media Settings are currently set to zero. To fix this, adjust the values according to the screenshot:?https://prnt.sc/J2lNpmtNyLq6.
If the issue continues even after implementing the above steps, please let me know, and I’ll be ready to help you further.
Thank you for your cooperation, and I look forward to hearing from you.