Hello, Abbas Aktas,
Thank you for reaching out to us with your concern.
Please read this article – https://www.8theme.com/documentation/xstore/xstore-builders/new-xstore-header-builder-with-elementor/
We kindly request that you navigate to Elementor > Settings > Features > Flexbox Container > change the value to “Active”, and try to import prebuild templates after that.
If you have any additional questions or concerns, please do not hesitate to reach out to us. Our support team is always available to assist you.
Best Regards,
8Theme’s Team