Hi @brein,
I hope you are well today and thanks for posting here.
It’s the known issue that you can resolve by downloading and using the latest version of Activello theme from this page https://github.com/puikinsh/Activello or using the Activello child theme shared in the following topic.
https://colorlibsupport.com/t/sidebar-at-bottom-of-page/#post-55341
Best Regards,
Movin