Issue in CheckMK Patch Day Plugin when processing regex

[DirkHoelscherKH]

If I exclude some "unwanted updates" in the agent rules of CheckMK plugin "Windows Patch Day”, the regex expression does not work as expected. If the exclude is (to exclude updates with the shown KB-numbers) it don't exclude these updates in the agent output. The $filter_regex in windows_patch_day.ps1 has the value (?i)^(KB2267602|KB4052623) so it looks right.

If the exclude in agent rule is the content of $filter_regex will be escaped as This completely destroys the regex expression.

Used version is 2.3.1 on Checkmk Enterprise Edition 2.3.0p12

Is this a bug or how exactly are the unwanted updates has to be defined?