WordPress Admin Page Slow. Customer Post Type is the slowest

The admin page loads slowly ever since adding Custom Post types. I’ve added them using CPT UI and Custom Fields plugins in WordPress. Whenever you click on the Custom post type from the sidebar it takes 8.74s to load. With one of the queries showing as “slow” according to debug bar plugin. See screenshot.

Context: I’ve created a site that hosts advertiser listings. We have about 700 advertisers with 20 fields.

How would one fix these load times? Does someone notice anything odd in the query?

Screenshot of debug bar details