Apologies for the delay in getting back to you on this.
WP Bakery is, TBH, not a great page builder plugin. The problem with it is that it adds lots of shortcodes to the page content, as you can see in your screengrab. These shortcodes will appear in the
content.rendered property of the post/page so Frontity will just render these shortcodes as part of the content.
If it’s possible for you to do so for your project I would suggest using Elementor if you need a page builder plugin. Elementor does not add shortcodes to the content, in the way that WP Bakery and other page builders like Divi do.