2 small files slowing down wordpress

Hi everyone
I’m optimizing my website speed. everything is good except for 2 very small files taking ages to load.
As you can see the website is taking 4 seconds to load, but on the waterfall, you can see that everything loads within the first 2 seconds except for (sometimes I retest and it takes 8-14 seconds to load due to the same 2 files):
https://theeltschool.com/?wc-ajax=get_refreshed_fragments
https://theeltschool.com/wp-admin/admin-ajax.php?0.9066150828610771
I’m not sure what are those especially since they are showing in red.
could you help, please?

P.S. a link for a slower test (the response time is high because I was overloading the server) https://gtmetrix.com/reports/theeltschool.com/MDJEuVKu/

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