It seems that info.magnolia.marketingtags.model.ScriptsAreaModel.isChildNodeOf is not taking into consideration variants in some cases. I tested it and it can be reproducible in the latest version of the module.

Steps to reproduce (in travel demo):
1. Create a page variant in travel home page.
2. Create a page variant in about page
3. Add segment Americas to about page variant
4. In Marketing tags, edit the tag an select 'Include in subpages' and '/travel'
5. Access the about page with personalization previewCountry parameter - travel/about?previewCountry=us

If you access to About page, it contains the tag if it is the original about page (without configuration).

If you access the variant via preview parameter, then the tag is not included, but if variant is visited via admincentral (pages app, preview app) than tag is included.

Since some issues have been detected integrating Marketing Tags + Personalization, it would be great if we could do some deeper testing on this.