I'm still struggling with External Images. Could you please check if the custom fields have been setup correctly in these imports?
Import ID 20 & 22: The featured images imported correctly, but when the image URL is changed on the XML file, it doesn't get replaced during the import so many images are missing.
Import ID 21, 23, 24 & 25: These are variation images and are not all importing.
Please take a look at this KB article for how to force External Images to recheck imported images:
I’m guessing you have the do_action setting switched off in WP All Import for faster imports – that’s fine, but you just need to reset another meta field in that case so that External Images will recheck the external_image_url field.
Hopefully that fixes all your issues, but if not let me know and I’ll investigate further.