Hello, @Kazi Sabit,
The code you added in the child theme to customize the site is not optimized that’s why it’s causing the issue. We cannot cover customization issues in our support policy. You have to optimize the code and check that code is causing the issue to solve it.
OR If you want paid Customization services submit a customization request to WPKraken team.
Regards 8Themes Team.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.