Error deleting Calendar Event

Version 9.1.2. PHP 8.0.8

I am getting the following error when trying to delete a calendar event…

Exception Occurred: /Applications/MAMP/htdocs/innovation_hubs_v912/concrete/src/Calendar/Event/EventService.php:226 Undefined property: Concrete\Core\Calendar\Event\EventService::$cID (2)

Weirdly it seems to be the second entry on the calendar that throws up the error?

When I switch to PHP 7.4 the issue no longer occurs?

Has anyone else come across this or shed some light on what might be causing the issue?

I’ve found the cause of this issue, and proposed a fix for it: see Fix handling of page removal when deleting a calendar event by mlocati · Pull Request #10971 · concretecms/concretecms · GitHub