When accepting invitations in KOrganizer, the category is not synced to NextCloud

Steps to reproduce

• Accept an invitation in Korganizer.
• View the invitation in the NextCloud calendar.
• All fields have the expected contents except the category.

Expected behavior

The category of an accepted invitation is synced to NextCloud calendar, too.

Actual behavior

When accepting invitations in KOrganizer, the category is not synced to my NextCloud calendar.
When creating an invitation myself for other attendies, the category is synced.

Calendar app version

6.5.3

CalDAV-clients used

korganizer-26.04.3-1.2

Browser

korganizer-26.04.3-1.2

Client operating system

openSUSE Tumbleweed 20260812

Server operating system

openSUSE Leap 16.0

Web server

Apache

Database engine version

MariaDB

PHP engine version

PHP 8.4

Nextcloud version

34.0.3

Updated from an older installed version or fresh install

Updated from an older version

List of activated apps

Enabled:
  - appstore: 1.0.0
  - calendar: 6.5.3
  - circles: 34.0.0
  - cloud_federation_api: 1.18.0
  - comments: 1.24.0
  - contacts: 8.7.6
  - dashboard: 7.14.0
  - dav: 1.40.0
  - federatedfilesharing: 1.24.0
  - files: 2.6.0
  - files_downloadlimit: 5.2.0
  - files_external: 1.26.0
  - files_lock: 34.0.1
  - files_pdfviewer: 7.0.0-dev.0
  - files_reminders: 1.7.0
  - files_sharing: 1.26.0
  - files_trashbin: 1.24.0
  - files_versions: 1.27.0
  - logreader: 7.0.0
  - lookup_server_connector: 1.22.0
  - mail: 5.10.12
  - nextcloud_announcements: 6.0.0
  - notes: 6.0.1
  - notifications: 7.0.0-dev.1
  - oauth2: 1.22.0
  - office: 1.0.0
  - password_policy: 6.0.0-dev.0
  - photos: 7.0.0
  - privacy: 6.0.0-dev.1
  - profile: 1.3.0
  - provisioning_api: 1.24.0
  - related_resources: 5.0.0-dev.0
  - serverinfo: 6.0.0
  - settings: 1.17.0
  - theming: 2.9.0
  - twofactor_backupcodes: 1.23.0
  - twofactor_totp: 16.0.0
  - updatenotification: 1.24.0
  - user_migration: 10.5.0
  - user_status: 1.14.0
  - viewer: 7.0.0-dev.0
  - webhook_listeners: 1.6.0
  - workflowengine: 2.16.0
Disabled:
  - activity: 7.0.0 (installed 2.14.3)
  - admin_audit: 1.24.0
  - app_api: 34.0.0 (installed 32.0.0)
  - bruteforcesettings: 7.0.0 (installed 1.1.0)
  - contactsinteraction: 1.15.0 (installed 1.2.0)
  - encryption: 2.22.0
  - federation: 1.24.0 (installed 1.4.0)
  - firstrunwizard: 7.0.0-dev.0 (installed 2.10.0)
  - recommendations: 7.0.0 (installed 0.6.0)
  - sharebymail: 1.24.0 (installed 1.8.0)
  - support: 6.0.0 (installed 1.4.0)
  - survey_client: 6.0.0-dev.0 (installed 1.2.0)
  - suspicious_login: 12.0.0-dev.0
  - systemtags: 1.24.0 (installed 1.11.0)
  - testing: 1.23.0
  - text: 8.0.0 (installed 1.1.1)
  - twofactor_nextcloud_notification: 8.0.0
  - user_ldap: 1.25.0
  - weather_status: 1.14.0 (installed 1.1.0)

Nextcloud configuration

Web server error log

Log file

Browser log

Additional info

No response

Reproduce the issue with KOrganizer 26.04.3 and Nextcloud Calendar 6.5.3 by accepting an invitation, then compare the accepted event with an invitation created by the user. No files or tests are identified in the report; done means the accepted invitation's category is visible after CalDAV synchronization, with regression coverage for both invitation paths.