Built‑in Android Exchange sync fails to pull calendar from Z‑Push

[Rezashelby]

When adding my Z‑Push account via Android Settings → Accounts → Add account → Exchange, mail and contacts sync correctly, but calendar events initially appear in the system calendar provider and then disappear after a short time. As a result, the Google Calendar app never shows up‑to‑date events, and it cannot create or delete events via ActiveSync. The same Z‑Push endpoint works reliably with Nine and Outlook, confirming the server side is functional.

Z-Push version: 2.7.5

Backend: CalDAV (Radicale)

PHP version: 8.3