org calendar doesn't show caldav events

[artelse]

My org-caldav setup is as follows:

(use-package org-caldav
    :init
    ;; calendar configurations
    (setq org-agenda-files (list "calendars/calendar.org" "calendars/org-test.org"))
    (setq org-caldav-url "https://bla.bla:1443/remote.php/dav/calendars/user/")
    (setq org-caldav-calendars
          `((:calendar-id "org-test"
                          :files ,(org-agenda-files)
                          :inbox ,(concat org-directory "calendars/org-test.org"))))
    :config
    (setq org-icalendar-alarm-time 1)
    (setq org-icalendar-timezone "Europe/Amsterdam")
    )

My org-id-extra-files also point to the org-agenda-files variable. org-caldav-sync downloads events and stores in inbox:

* Event1
:PROPERTIES:
:ID:       3709F8BA-E938-4EF5-9F09-5F558FC355B5
:END:
<2021-12-16 Thu 10:00-11:00>
* Event2
:PROPERTIES:
:ID:       BDE8B832-4816-4B96-9888-763F4B4E0EE4
:END:
<2021-12-17 Fri 10:00-11:00>
* Event3
:PROPERTIES:
:ID:       3AC63D6D-358A-47BB-8790-3F44CD05A2A3
:END:
<2021-11-24 Wed>

But my calendar.org file remains empty and therefor org calendar or agenda won't show any events. Any ideas?