Android Question Delay in arrival on Android smartphone of fcm notifications sent from pc

Private Sub SendMessage(Topic As String, Title As String, Body As String)
    Dim Job As HttpJob
    Job.Initialize("fcm", Me)
    Dim m As Map = CreateMap("to": $"/topics/${Topic}"$)
    Dim data As Map = CreateMap("title": Title, "body": Body)
    If Topic.StartsWith("ios_") Then
        Dim iosalert As Map =  CreateMap("title": Title, "body": Body, "sound": "default")
        m.Put("notification", iosalert)
        m.Put("priority", 10)
        End If
    m.Put("data", data)
    Dim jg As JSONGenerator
    jg.Initialize(m)
    Job.PostString("https://fcm.googleapis.com/fcm/send", jg.ToString)
    Job.GetRequest.SetContentType("application/json;charset=UTF-8")
    Job.GetRequest.SetHeader("Authorization", "key=" & Fcm_Server_Key)
End Sub

Sub JobDone(job As HttpJob)
    Log(job)
    If job.Success Then
        Log(job.GetString)
    End If
    job.Release
    ExitApplication '!
End Sub

m.Put("android", CreateMap("priority": "high"))

"android": {"priority": "normal"}

"webpush": {"headers": {"Urgency": "high"}}