Surfing in the settings, I came across the Security tab, sorted below the Diagnostics header. Once there, I was greeted by a reassuring message that something was amiss. It had a warm orangy-tinted background and carried just the right amount of urgency to do exactly as it said:
WARNING: PATH TO MATOMO/plugins/SecurityInfo/PhpSecInfo/Test/Application/php.php(39): Notice - Trying to access array offset on value of type bool - Matomo 4.1.0 - Please report this message in the Matomo forums: https://forum.matomo.org (please do a search first as it might have been reported already) (Module: SecurityInfo, Action: index, In CLI mode: false)
But maybe, I am just the conscientious kind of person.
Anyways. Thanks for the great product. If you need more info I’m happy to help.