"Updating search indexes" message in admin sidebar
Since you're on Craft 3.2+, the Update Asset Indexes Utility has been removed in favor of the craft resave console command, which will update the search indexes as a side-effect of re-saving the element and it gives you much more fine-grained control over which elements/search indexes to resave.

Will update the docs you linked to reflect that.

To debug your failed job in the queue, I'd start by searching the queue.log file in the Craft logs folder for the underlying error message.