Delay with the coach interface on Kolibri

Hello,
We have installed Kolibri on Rachel 2.0 and have been using it for quite sometimes. I have read that the version of 0.13 will solve the lag on the coach interface but it is not the case on our site.
Whenever we click on the coach (be for checking the report, creating quizzes, etc…) it takes more than 10 mins to respond and sometimes it just doesn’t respond. Is there anything I can do to stop that? It is really affecting classes

Kolibri info:

Version: 0.13.0
OS: Linux-3.10.61-ltsi-06292015-x86_64-with-Ubuntu-14.04-trusty
Installer: apt
Server: Kolibri internal server
Database: /root/.kolibri/db.sqlite3
Device name: WAPD-235N-Server
Free disk space: 1 GB
Server time: Wed Feb 05 2020 13:14:25 GMT+0200 (Central Africa Time)
Server timezone: America/Los_Angeles

Kolibri log file