Calendar events show undefined in title/name

[jawaite123]

Checklist

• [X ] I have updated to the latest available Home Assistant version.
• [X ] I have cleared the cache of my browser.
• [X ] I have tried a different browser to see if it is related to my browser.

The problem

The calendar tab shows events, but all have "undefined" as their title. The events are from iCloud calendars using the caldav platform.

Expected behavior

I expect that the event title, i.e. Lunch with Brian, would show in the calendar

Steps to reproduce

1. add caldav calendar to configuration.yaml
2. Navigate to the Calendar tab in Lovelace

Environment

arch | x86_64
chassis | desktop
dev | false
docker | true
docker_version | 19.03.13
hassio | true
host_os | Debian GNU/Linux 10 (buster)
installation_type | Home Assistant Supervised
os_name | Linux
os_version | 4.19.0-12-amd64
python_version | 3.8.6
supervisor | 2020.11.0
timezone | America/New_York
version | 0.117.6
virtualenv | false

• Home Assistant release with the issue: Ever since calendar tab appeared in Lovelave
• Last working Home Assistant release (if known): None
• Browser and browser version: Chrome Version 86.0.4240.193
• Operating system: HASS runs on Debian 10 | Client is Windows 10

Problem-relevant configuration

calendar:
  - platform: caldav
    username: "xxx@xx.com"
    password: "xxx"
    url: "https://xxx.icloud.com/"
    calendars:
      - 'Family' 

[asystentka-jolka]

I noticed similar problem with google calendars but it was not a bug in HA but this came from calendars settings.
Event details were hidden by default in google calendars settings, only free/busy info was returned.
After changing settings like on this picture below it works OK

[github-actions]

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates.
Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍
This issue has now been marked as stale and will be closed if no further activity occurs. Thank you for your contributions.