Redmine

Hi,
I've recently installed Redmine 3.3.1 on Debian Stretch and I think I have found a bug regarding the "issues" page. As you can see from the screenshots provided, the parameters "Duration", "Story points" and "Velocity based estimate" aren't properly presented in the web page. I've take a look into the web page source code using Chromium Inspector and it looks like these parameters, and there values, are somehow injected, without any html tags, into the page by Redmine. I also looked at the file ./app/views/issues/show.html.erb and compared it with previous Redmine versions in Github and didn't found any major difference. However, it looks like these parameters (such as "Duration") aren't even called in this file.
Thanks.

Here's some useful informations:

ruby bin/about

Environment:
Redmine version 3.3.1.stable
Ruby version 2.3.3-p222 (2016-11-21) [x86_64-linux-gnu]
Rails version 4.2.7.1
Environment production
Database adapter Mysql2
SCM:
Subversion 1.9.5
Git 2.11.0
Filesystem
Xitolite 2.11.0
Redmine plugins:
clipboard_image_paste 1.12
redmine_announcements 1.0
redmine_backlogs v1.0.6
redmine_better_gantt_chart 0.9.0
redmine_bootstrap_kit 0.2.5
redmine_dmsf 1.5.9
redmine_git_hosting 1.2.3
redmine_image_clipboard_paste 3.3.0
redmine_issues_summary_graph 0.0.9
redmine_landing_page 0.1.1
redmine_monitoring_controlling 0.1.1
redmine_my_page_queries 0.1.0
redmine_sidekiq 2.1.0
redmine_silencer 0.4.3
redmine_stealth 0.7.2
scrum2b 2.0

lsb_release -a

No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 9.4 (stretch)
Release: 9.4
Codename: stretch

uname -a

Linux redmine 4.9.0-6-amd64 #1 SMP Debian 4.9.88-1+deb9u1 (2018-05-07) x86_64 GNU/Linux