How to remove ^null$ errors from Logwatch?

Question

linux

After switching to HTTPS, Logwatch displays ^null$ errors (connection closed before receiving a response from the server) for all hosts that access the site.
How to remove this error?
When testing through https://2ip.ru/server-response/ it gives:

HTTP/1.1 200 OK

In the Logwatch report itself:

*.** MB transferred in 7645 responses (1xx 7645, 2xx 0, 3xx 0, 4xx 0, 5xx 0)

Answer 1

The problem was the wrong format of the Apache log files. I returned the default log format in the apache2.conf file and everything began to work correctly:

LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\""