WARNING: /var/www/plugins/Live/Controller.php(99): Notice - Undefined variable: visitors - Matomo 3.13.0 (Module: Live, Action: widget, In CLI mode: false)

Support & Bugs
1

Got this when viewing this page:
/index.php?module=MultiSites&action=index&idSite=8&period=week&date=today

Unable to reproduce, but wanted to share in case anyone understands why this occurred.