Only Level 1 headings syncing even though IDs are assigned

[code-SL]

Syncing two-way is working well, but only for headlines at level 1. Is this expected behavior? I am only syncing DEADLINE marked entries, but these entries are at multiple levels some at level 1, 2, etc.

IDs are being assigned on the right entries (i.e. even non-level-1 headlines, which is expected behavior), but only level 1 headlines are actually being exported to the icalendar export (and thus being synced).

See below config.

(use-package org-caldav
  :straight (org-caldav :type git :host github :repo "dengste/org-caldav")
  :config
  (setq org-caldav-url "myurl.com/foo/bar")
  (setq org-caldav-calendar-id "orgmode")
  (setq org-caldav-inbox "baz.org")
  (setq org-caldav-debug-level 2)
  (setq org-caldav-files nil)
  (setq org-caldav-sync-todo t)
  (setq org-icalendar-include-todo 'all)
  (setq org-caldav-skip-conditions '(notdeadline))
  (setq org-caldav-save-directory "bazdirectory")
  (setq org-icalendar-timezone "America/New_York")
  (setq org-caldav-sync-on-save t)
  (setq org-caldav-delete-org-entries 'ask)
  )