Live Activity Update: `apns-priority` does not seem to be respected when lowered from "10"

[barfoon]

Description

https://firebase.google.com/docs/cloud-messaging/customize-messages/live-activity#rest

Using Firebase FCM via HTTP POST to my cloud function endpoint, the live activity update is always delivered with the highest, most intrusive priority (and visually alerts the user, pops the activity down briefly from the dynamic island etc)

If I set this to "5" - it still seems to be delivered at the highest priority - why?

const message = {
    token: activity.fcmToken,
    apns: {
        "live_activity_token": cleanPushToken,
        headers: {
            "apns-priority": scoreData.priority,
            "apns-push-type": "liveactivity"
        },
        payload: {
            aps: {
                timestamp: Date.now(),
                event: "update",
                "content-state": {
                    homeGoals: scoreData.homeGoals,
                    visitorGoals: scoreData.visitorGoals,
                    gameStatus: scoreData.gameStatus
                },
                alert: {
                    title: `${scoreData.homeTricode} vs ${scoreData.visitorTricode}`,
                    body: `${scoreData.homeTricode} ${scoreData.homeGoals} - ${scoreData.visitorGoals} ${scoreData.visitorTricode}`
                }
            }
        }
    }
};

Also according to the docs
https://developer.apple.com/documentation/usernotifications/sending-notification-requests-to-apns

We can set this value also to "1" - but when I do this I get an invalid priority error. Can this priority be supported?

How can I deliver Live Activity updates with a lower priority via FCM?

Thank you,

Reproducing the issue

No response

Firebase SDK Version

11.6.0

Xcode Version

26.0.1

Installation Method

Swift Package Manager

Firebase Product(s)

Messaging

Targeted Platforms

iOS

Relevant Log Output

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[rizafran]

Thanks for reporting, @barfoon. Per checking, apns-priority 1 is currently not supported, but it should work on 5. Based on our docs, apns-priority 5 or normal priority messages are delivered immediately when the app is in the foreground. With this, may I know if the messages are still being delivered immediately even on background when setting the priority to 5?