In my Moodle (3.9.2) im getting extremely high cpu usage from a 60 or so user concurrency. Both my db and webserver are on the same server as well as a small wp site, 8 cores 16ram. All of my 8 cores are always at 95%+ usage from MySql. As soon as i reboot my server it goes back up to full consumption. Ram consumption is at 3gb.
Checking on phpmyadmin active processes is mostly composed of "select from moodle_coruse_mdl_completions" queries.
Php version 7.2
Mysql version 5.6.35
Any ideas of what might be causing this?