UCMA Bot Stop handling CallReceivedEvent after some minutes of inactivity

Hi, I'm facing a rare problem, I've develop a Bot that is answering im calls, and it is working as expected whiout troubles Recently I've created a second bot, with similar configurations, conected to the same Lync 2010 server, Same source code that the previous one.  The new one runs ok after started and providing responses when a user make a im call, etc.

But After some minutes (between 15 ~ 30) of inactivity (I mean  nobody make new calls neither writing on established calls) the bot is stop or handling CallReceivedEvents...

The CollaborationPlatform is alive.. and the Application endpoint too, but the Event of

InstantMessagingCallReceived(ByVal sender As Object, ByVal e As Microsoft.Rtc.Collaboration.CallReceivedEventArgs(Of Microsoft.Rtc.Collaboration.InstantMessagingCall)) is not being fired when a user try to connect. this event is handled when initilize the Appendpoint as it is show below:

      ThisEndpoint.RegisterForIncomingCall(Of InstantMessagingCall)(AddressOf InstantMessagingCallReceived)

I ve to Re-initialize the  CollaborationPlatform in order to get the event fired againplease Any suggestion will be really appreciated or any comment about how to debug it.

thanks in Advance

Below are details of the object and a sample of the error

When contacting your support team, reference error ID 504 (source ID 239)

?CollaborationPlatform
{Microsoft.Rtc.Collaboration.CollaborationPlatform}
    ActiveGruu: "sip:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx;gruu;opaque=srvr:dvlyncprd.application:X_lqwt1_rlaff-8bVmgPkAAA"
    ActiveListeningIPEndpoint: {[::]:5061}
    AllowedAuthenticationProtocol: Ntlm Or Kerberos {3}
    AllowNoAuthentication: True
    ApplicationTopologyData: Nothing
    ApplicationUserAgent: "xxxxxxxxx.application"
    AudioVideoSettings: {Microsoft.Rtc.Collaboration.AudioVideo.AudioVideoSettings}
    Capabilities: Count = 4
    ConnectionManager: {Microsoft.Rtc.Signaling.RealTimeServerTlsConnectionManager}
    ContainsDefaultRoutingEndpoint: False
    CurrentMessageThrottlingCount: 0
    DefaultAudioVideoProviderEnabled: True
    DefaultAudioVideoProviderInitialized: True
    InstantMessagingSettings: {Microsoft.Rtc.Collaboration.InstantMessagingFlowTemplate}
    IsAutoProvisionedPlatform: False
    IsClientPlatform: False
    IsCommunicationServerTestPlatform: False
    IsIpv6StackModeDisabled: False
    ListeningIPAddress: {::}
    Localhost: "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    OutboundConnectionDefaultAddressFamilyHint: Nothing
    PlatformExtensionManager: {Microsoft.Rtc.Collaboration.PlatformExtensionManager}
    ProvisioningSource: Nothing
    SharedProvisioningData: {Microsoft.Rtc.Collaboration.SharedProvisioningData}
    StackHint: Dual {0}
    State: Started {2}
    SupportedMediaTypes: Count = 4
    TimerWheel: {Microsoft.Rtc.Signaling.TimerWheel}
    TopologyConfiguration: Nothing
    Transport: Tls {2}

ApplicationEndpoint

Microsoft.Rtc.Collaboration.ApplicationEndpoint}
    ApplicationQueue: {Microsoft.Rtc.Signaling.WorkitemQueue}
    AutoAcceptInterval: {00:00:25}
    BypassDomainSuffixCheckEnabled: False
    CachedMediaRelayToken: {Microsoft.Rtc.Internal.Collaboration.CachedMediaRelayToken}
    ConferenceServices: {Microsoft.Rtc.Collaboration.ConferenceManagement.ConferenceServices}
    ContactGroupServicesInternal: Nothing
    DefaultDomain: "xxxxxxxx.com"
    DrainingModeInternal: None {0}
    EndpointSubtype: Attendant {3}
    EndpointSubtypeAttendant: "attendant"
    EndpointSubtypeFeatureParameterName: "actor"
    EndpointSubtypeInformation: "information"
    EndpointSubtypeMessageTaker: "msg-taker"
    EndpointSubtypePrincipal: "principal"
    EndpointType: Application {1}
    EndpointTypeApplication: "automata"
    EndpointTypeConference: "isFocus"
    EndpointTypeGateway: "isGateway"
    EndpointUri: "sip:xxxxxxxxxxxxx;gruu;opaque=srvr:dvlyncprd.application:X_lqwt1_rlaff-8bVmgPkAAA"
    InnerEndpoint: {sip:xxxxxxxxx}
    IsAnonymousEndpoint: False
    IsAutomaticPresencePublicationEnabled: True
    IsAutoProvisioned: False
    IsDefaultRoutingEndpoint: False
    IsDefaultRoutingEndpointInternal: False
    IsDnsServerDiscoveryNeeded: False
    IsInitialized: True
    IsOutsideCorporateNetwork: False
    IsOwnerDeleted: False
    IsPresenceInitializationNeeded: True
    IsTerminatingOrTerminated: False
    IsTerminationRequested: False
    LocalOwnerPresence: {Microsoft.Rtc.Collaboration.Presence.LocalOwnerPresence}
    MaxRegisterRetries: 1
    MediaRelayToken: {OwnerUri=sip:xxxxxxxxxxxxx;gruu;opaque=srvr:dvlyncprd.application:X_lqwt1_rlaff-8bVmgPkAAA,UserName=AgAAJFWvxlsBzwszVTUpRGCXX0f6GJMwzU4bfgHmfH0AAAABrhkjg6y79950mgJ1Apn13FXUE7E=,Duration=480   relay=xxxxxxx=>tcp:443,udp:3478   relay=xxxxxxxxxx=>tcp:443,udp:3478  }
    MicrosoftLocationProfileAccept: "application/ms-location-profile-definition+xml"
    MicrosoftLocationProfileContentType: "application/ms-location-profile-definition+xml"
    MicrosoftLocationProfileUriParameters: ";gruu;opaque=app:locationprofile:get;default"
    NextHopInformation: {Microsoft.Rtc.Signaling.ConnectionContext}
    OutboundConnectionDefaultAddressFamilyHint: Nothing
    OwnerDisplayName: "xxxxxxxxx"
    OwnerPhoneUri: ""
    OwnerProperties: {Microsoft.Rtc.Internal.Collaboration.ApplicationEndpointOwnerProperties}
    OwnerUri: "sip:xxxxxxxx"
    OwnerVoicemailUriInternal: "sip:xxxxxxxx;opaque=app:voicemail"
    PhoneContext: "arg_buenosaores_site"
    PinServices: {Microsoft.Rtc.Collaboration.PinManagement.ApplicationPinServices}
    Platform: {Microsoft.Rtc.Collaboration.CollaborationPlatform}
    PreferredMediaRelayContext: {Mras Uri = sip:xxxxxxxxx;gruu;opaque=srvr:MRAS:5YXYpsjpElWEk-c1CcdmbwAA Source = Provisioning}
    PreferredServiceCapabilities: {Microsoft.Rtc.Collaboration.PreferredServiceCapabilities}
    PresenceBasedScreeningDisabled: False
    PresencePublicationOperationId: "PresencePublicationNoOpOperationId"
    PresenceServices: {Microsoft.Rtc.Collaboration.ApplicationEndpointPresenceServices}
    PresenceServices (LocalEndpoint): {Microsoft.Rtc.Collaboration.ApplicationEndpointPresenceServices}
    ProvisioningDataDisabled: False
    ProvisioningDataQueryDisabled: False
    ProvisioningDataQueryDisabledInternal: False
    PublishingQoeMetricsDisabled: False
    RegisterMethods: ""Service,Notify,Benotify,Message,Info,Options,Invite""
    RegistrarKey: "sip:xxxxxxxx;gruu;opaque=srvr:HomeServer:a0Z40GPgeVqllqZf7Ps_IwAA"
    RegistrationDisabled: False
    RejectInvitesWithoutStaticRegistrationHeader: False
    RemotePresence: {Microsoft.Rtc.Collaboration.Presence.RemotePresence}
    RemotePresenceSessionManager: {Microsoft.Rtc.Collaboration.Presence.RemotePresenceSessionManager}
    RichPresenceSupportedHeaders: Count = 2
    State: Established {2}
    SupportedMimePartContentTypes: Count = 0
    SyncRoot: {Object}
    TimerWheel: {Microsoft.Rtc.Signaling.TimerWheel}
    TraceFilterConfiguration: Nothing
    UserAgent: "RTCC/5.0.0.0 xxxxxxx.application"
    UseRegistration: True
    UserServicesState: Available {1}
    WebServerSourceNetwork: Nothing
    WillProvisioningQueryAlwaysFail: False
    WorkItemQueue: {Microsoft.Rtc.Signaling.AsyncWorkitemQueue}