Ajax calls are causing 504 errors in wp-admin dashboard on wpengine

Our site, https://brownfieldagnews.com/, is hosted by wpengine. We were having issues recently with users being unable to login to the wp-admin. WpEngine was able to make several updates but also said this:

I can also see that the server is under a lot of strain from the wp-most-popular plugin, which is known to produce a high number of admin-ajax calls, and overwhelm servers. Reducing the number of ajax calls from this plugin would not only ensure
fewer 504 errors, but also speed up your server’s response time tremendously. I would suggest contacting the plugin developers, and working with them to reduce the number of admin-ajax calls made by the plugin

With that being said, I’m hitting up the support board to see what can be done to address this issue. I don’t know why the wp-admin would be getting ajax requests via this plugin but any advice/tips would be great.

The page I need help with: [log in to see the link]