“WP_JSON” causing over 10 seconds of page load time

I’ve been looking into why my website takes a long time to load. After checking with GTMetrix and other tools such as Pingdom, there seems to be an issue on the initial loading of the site.

The first thing to load is “GET mydomain”. With the link “<https://mydomain/wp-json/&gt;; rel=”https://api.w.org/&#8221;, <https://mydomain/&gt;; rel=shortlink”. This takes a long 12.85 seconds to load, once finished everything else loads. So a total loading time of over 20 seconds.

I’ve tried disabling all plugins to see if that could be causing an issue. The load time drops slightly to 10.54 seconds but total page load time 11.8 seconds. So not exactly shaving much off the loading time.

If anyone would be able to provide any assistance as to how I can rectify and fix this problem, it would be most appreciated.

Thank you!