I am using Rankmath with Flatsome.
As per Rankmath Support -
"The UX Builder uses a custom implementation of the custom fields to add content to the page like images, internal links, and Rank Math is not able to fetch them from those fields to analyze.
The way to achieve this integration would be for the team of Flatsome/UX Builder to implement our Content Analysis API: https://rankmath.com/kb/content-analysis-api/
You can contact the developers of the theme and show them the link above."
Is there a possibility of Flatsome developers doing it?