Hi, @ktamb , welcome to Tainacan’s site.
You are likely experiencing the same thing I had here:
The solution is to optimize the WP DB indexes and one plugin I’ve been using on Tainacan and WP in general clients is the “Index WP MySQL For Speed”. It changes the database indexes to a much faster setup. I’ve seen significant improvements on both Tainacan and WordPress blogs and applications that rely on WP tables.
Like any database change, please backup your site and data before trying it. I’ve never had an issue, but it has the potential to break your whole database if anything goes wrong.
Hope it helps!