This is a bug report about a moderator-only feature.
Recently, the user comments history page was revamped, and bulk actions as well as comments search was implemented. Both work fine separately.
However, after performing a search (AJAX call), the bulk actions "Select all" checkbox no longer functions, and clicking on it does not select/unselect all the search results.
Also, selecting any of the individual checkboxes below does not enable the bulk actions "Actions" dropdown at the top.
Windows 10 Chrome Version 81.0.4044.138 (Official Build) (64-bit), userscripts switched off