Sidebar getting removed when adding a header

Today I have purchased a pro version and to be frank, I am a bit disappointed, I created a header template by following all the steps. but when I enable the header, the right sidebar gets removed from the website. I have tried all possible options and tested it with multiple headers but could not resolve the issue.

Page with no elementor header (with sidebar) – https://algorithms.tutorialhorizon.com/convert-number-to-base-3-string-representation/

Page with elementor header (sidebar removed) – https://algorithms.tutorialhorizon.com/print-first-n-prime-numbers-java-code/

The page I need help with: [log in to see the link]