Filtering is not occurring for content of Questionnaire activity's 'Advanced Settings' tab 'Additional Info' setting.

In my case this was the filtercodes plugin I was trying to get working; however the issue is for all filter plugins.

The problem is due to the output of the setting's content not getting passed through format_text() function or format_string() function (see https://docs.moodle.org/dev/Output_functions)

When I pass the content through 'format_text()' then the issue resolves itself.