Hello,
You can use the Elementor, but in this case content of pages should be created from scratch, because it is a bad practice to edit 1 page using 2 editors.
I can see these error https://prnt.sc/v7nj80 when saving WPBakery page. On first sight it doesn’t relate to the theme and can be caused by one of 3rd party plugins on your site.
Try to disable all the third-party plugins, that do not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins , and check how it works then.
Also, update plugins – https://prnt.sc/v7nlcv , follow this article – https://xstore.helpscoutdocs.com/article/37-plugins-update
Regards