WearOS 3: How to get updates on calendar events for a custom complication?

I'm trying to create a custom WearOS complication that shows the title of the next event. The watch has a built-in Agenda app that synchronizes with the phone's calendar. There is also a built-in complication that shows the time of the next event, from the same Agenda app. When I change the next event in my phone (the time and the title), the complication updates immediately (it takes 5-10 seconds) and the new information is also available in the watch's Agenda app. I want my complication to do the same, but it just doesn't update.

So far, I've created a SuspendingComplicationDataSourceService as follows:

class ComingEventComplication : SuspendingComplicationDataSourceService() {
    
    override suspend fun onComplicationRequest(request: ComplicationRequest): ComplicationData? {
        val nextEvent = getNextCalendarEvents(this.contentResolver)[0]

        return if (nextEvent != null) {
            //Expose data to the complication
        } else {
            //Show a placeholder
        }
    }

    //Preview data
    override fun getPreviewData(type: ComplicationType): ComplicationData? {
        [...]
    }
}

I'm not showing the code to expose the data to make it shorter (but it works). The getNextCalendarEvents() function is the following:

fun getNextCalendarEvents(contentResolver: ContentResolver): List<CalendarEvent> {
    val events = mutableListOf<CalendarEvent>()

    // Define the projection (columns you want to retrieve)
    val projection = arrayOf(
        CalendarContract.Instances.EVENT_ID,
        CalendarContract.Instances.TITLE,
        CalendarContract.Instances.DESCRIPTION,
        CalendarContract.Instances.EVENT_LOCATION,
        CalendarContract.Instances.BEGIN,
        CalendarContract.Instances.END,
        CalendarContract.Instances.ALL_DAY
    )

    val startMillis = System.currentTimeMillis()
    val endMillis = startMillis + TimeUnit.DAYS.toMillis(5)

    val uriBuilder = WearableCalendarContract.Instances.CONTENT_URI.buildUpon()
    ContentUris.appendId(uriBuilder, startMillis)
    ContentUris.appendId(uriBuilder, endMillis)
    val uri = uriBuilder.build()

    // Query the Content Provider
    val cursor = contentResolver.query(
        uri,
        projection,
        null,
        null,
        null
    )

    cursor?.use {
        while (it.moveToNext()) {
            val eventId = it.getLong(it.getColumnIndexOrThrow(CalendarContract.Instances.EVENT_ID))
            val title = it.getString(it.getColumnIndexOrThrow(CalendarContract.Instances.TITLE))
            val description =
                it.getString(it.getColumnIndexOrThrow(CalendarContract.Instances.DESCRIPTION))
            val location =
                it.getString(it.getColumnIndexOrThrow(CalendarContract.Instances.EVENT_LOCATION))
            val beginTime = it.getLong(it.getColumnIndexOrThrow(CalendarContract.Instances.BEGIN))
            val endTime = it.getLong(it.getColumnIndexOrThrow(CalendarContract.Instances.END))
            val isAllDay =
                it.getInt(it.getColumnIndexOrThrow(CalendarContract.Instances.ALL_DAY)) == 1

            events.add(
                CalendarEvent(
                    id = eventId,
                    title = title,
                    description = description,
                    location = location,
                    startTime = Instant.ofEpochMilli(beginTime),
                    endTime = Instant.ofEpochMilli(endTime),
                    isAllDay = isAllDay
                )
            )
        }
    }

    return events.sortedBy { it.startTime }
}

with my custom data class:

data class CalendarEvent(
    val title: String,
    val startTime: Instant,
    val endTime: Instant,
    val isAllDay: Boolean,
    val description: String?,
    val location: String?,
    val id: Long
) 

Finally, my AndroidManifest setup is:

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission-sdk-23 android:name="android.permission.READ_CALENDAR" />
<uses-feature android:name="android.hardware.type.watch" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@android:style/Theme.DeviceDefault" >
    <meta-data
        android:name="com.google.android.wearable.standalone"
        android:value="true" />
<service
            android:name="developer.pion.complicationsprovider.services.ComingEventComplication"
            android:permission="com.google.android.wearable.permission.BIND_COMPLICATION_PROVIDER"
            android:exported="true"
            android:label="Test"
            android:icon="@drawable/common_full_open_on_phone">
            <intent-filter>
                <action android:name="androidx.wear.watchface.complications.action.COMPLICATION_DATA_SOURCE" />
            </intent-filter>
            <meta-data
                android:name="android.support.wearable.complications.SUPPORTED_TYPES"
                android:value="SHORT_TEXT" />

        </service>
    </application>

This part works as expected: I add the complication and it shows the name of the next event in my calendar. The problem comes when I change the next event in my calendar on my phone. The built-in complication updates but not mine (I have to re-add it again). So far I've tried adding a WorkManager to update the complication (which is not very reliable if you set it to schedule every long time, and it may drain the battery otherwise), and using a ContentObserver :

class ContentObserver(
    private val context: Context,
    private val componentName: ComponentName
) : ContentObserver(Handler(Looper.getMainLooper())) {

    override fun onChange(selfChange: Boolean, uri: Uri?) {
        super.onChange(selfChange, uri)
        Log.d("DEBUG_", "onChange: Changed!")
        requestComplicationUpdate()
    }

    private fun requestComplicationUpdate() {
        val requester = ComplicationDataSourceUpdateRequester.create(
            context = context,
            complicationDataSourceComponent = componentName
        )
        requester.requestUpdateAll()
    }
}

I do register my ContenObserver inside ComingEventComplication class:

override fun onCreate() {
    super.onCreate()
    val calendarUri: Uri = WearableCalendarContract.CONTENT_URI

    // Create the ContentObserver instance.
    calendarObserver = ContentObserver(
        context = applicationContext,
        componentName = ComponentName(applicationContext, ComingEventComplication::class.java)
    )

    // Register the observer.
    contentResolver.registerContentObserver(
        calendarUri,
        true,
        calendarObserver
    )
}

override fun onDestroy() {
        super.onDestroy()
        // Unregister the observer to prevent memory leaks.
        contentResolver.unregisterContentObserver(calendarObserver)
    }

The DEBUG_ onChange: Changed! is never shown in my logcat. I also tried adding a receiver in my manifest:

<receiver android:name=".receivers.CalendarUpdateReceiver"
    android:exported="true">
    <intent-filter>
        <action android:name="android.intent.action.PROVIDER_CHANGED" />
        <data android:scheme="content" android:host="com.google.android.wearable.provider.calendar" />
    </intent-filter>
</receiver>

setting the android:host as the Uri given by WearableCalendarContract.CONTENT_URI , WearableCalendarContract.Instances.CONTENT_URI and CalendarContract.CONTENT_URI . The receiver calls a dummy BroadcastReceiver that displays a log entry. I had no success with any of them.

Up to now I'm not sure if I'm setting something wrong or if I need a different approach. I've tested third-party complications that are able to update in less than a minute from the event change on phone, so I think there must be a reliable way of doing this. Any help will be appreciated!