Korganizer import iCloud read-only share

My boss has an iCloud calender of which I have an ics link (webcal://pxx-calendarws.icloud.com/ca/subscribe/…). I want to access this calender from Korganizer. I can create a new ical calendar resource and put the link as the source file without error. But no events are ever displayed or even fetched. I tried replacing webcal:// with https:// to no avail. I know there are tons of links on how to sync Korganizer with ICloud calenders via CalDav, but this is no option for me - I only have this link. Am I doing things wrong or is this a possible bug in Korganizer/Akonadi? I’d like to post more information but I don’t know how to get log messages from the calendar resource.

As a fallback I have Thunderbird/Lightning (which works with the link), but I’d like to use Kontact on my machine since it fits nicely into KDE. Any suggestions are appreciated!