Here is my (perlgolf) oneliner code:

As we do not have a terminator string, I used undef.
$M=1 when the match is found,
$M=2 on the first line after the match.

perl -ne 'if($M=/Update certificate/..undef){print if($M>1 && $M<=6)}'

to also print the matched line as well (header):

perl -ne 'if($M=/Update certificate/..undef){print if $M<=6}'

IMPORTANT: due to having no terminator string, it will only match once in a given file.