Bug or misconfiguration with mod_security ?

Hi,

On 2 ubuntu (16.10, 17.04) machines and on 1 debian 8.6 I've some 
strange behaviors.
First, I've installed logwatch and mod_security. Everything seems good 
in  /usr/share/logwatch
But in the report there is no section for mod_security.

So I've copied files in /etc/logwatch as described in documentation.
  /etc/logwatch/conf/services/mod_security2.conf
  /etc/logwatch/conf/logfiles/audit_log.conf
No section appears in report

Then I've change in 
/usr/share/logwatch/default.conf/services/mod_security2.conf
#LogFile = modsecurity2/modsec_audit.log
LogFile = apache2/modsec_audit.log
#Archive = modsecurity2/modsec_audit.log.*
Archive = apache2/modsec_audit.log.*

which seems more legit.

But there's still no  section in report except if I launch
logwatch --debug High

May I missed something ?

Cheers,
FAb

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