Calendar Spam addressees turn up in "Recently contacted"

Describe the bug

If you are an addressee of calendar spam and import a calendar with such spam into Nextcloud, the other adressees turn up in the contacts app under "Recently contacted" although they have not been recently contacted.

Steps to reproduce

1. Have an iCloud account with calendar data containing old calendar spam.

2. Export this calendar data to .ics files via macOS calendar.

3. Connect macOS calendar to Nextcloud as described here.

4. Import the .ics files into the Nextcloud calendar via macOS calendar.

5. Open the contacts app.

Expected behavior

The addressees of the calendar spam do not appear under "Recently contacted" because they have not been recently contacted.

Actual behavior

The addressees of the calendar spam do appear under "Recently contacted".

Contact version

6.2.0

Operating system

Raspberry Pi OS Lite (64-bit, Debian Bullseye)

PHP engine version

PHP 7.4

Web server

Other

Database

PostgreSQL

Additional info

I thought my account had been breached and spent an evening on figuring out how someone could have contacted these people through my Nextcloud account. Only once I dumped my database to find where the addresses have been persisted could I draw the connection to the calendar data.

If someone gets here via Google because mysterious email addresses allegedly have been recently contacted by you, check your calendar data for calendar spam.