"Failed to create endpoint [XXX] on network because of a duplicate name" on local 5-node Service Fabric cluster - azure-service-fabric

Question

I have a local Service Fabric cluster of 5 nodes and I have a problem deploying my application on all nodes. When set to "1 Node", the cluster works fine. When set to "5 Nodes" it gives an error on all nodes but one. This is the error/warning message:
Error event: SourceId='System.Hosting', Property='CodePackageActivation:Code:EntryPoint:131919316927686034'.
There was an error during CodePackage activation.System.Fabric.FabricException (-2147017731)
Failed to start Container. ContainerName=sf-0-28e0002f-fd7d-412c-81b8-b78ca5339ce4_865991cc-9c36-493f-9b3d-95f6eba43851, ApplicationId=Proton.SFType_App0, ApplicationName=fabric:/Proton.SF.
DockerRequest returned StatusCode=InternalServerError with ResponseBody={"message":"failed to create endpoint sf-0-28e0002f-fd7d-412c-81b8-b78ca5339ce4_865991cc-9c36-493f-9b3d-95f6eba43851 on network nat: HNS failed with error : You were not connected because a duplicate name
The error message looks truncated. The application loads up fine, but on one node only. Am I missing something in 5-node configuration? The application we are deploying is a container which runs a .NET Core app. I've attached a screenshot of the error in Service Fabric Explorer.
Error Screenshot
ServiceManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<ServiceManifest Name="Proton.TestingPkg"
Version="1.0.0"
xmlns="http://schemas.microsoft.com/2011/01/fabric"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<ServiceTypes>
<!-- This is the name of your ServiceType.
The UseImplicitHost attribute indicates this is a guest service. -->
<StatelessServiceType ServiceTypeName="Proton.TestingType" UseImplicitHost="true" />
</ServiceTypes>
<!-- Code package is your service executable. -->
<CodePackage Name="Code" Version="1.0.0">
<EntryPoint>
<!-- Follow this link for more information about deploying Windows containers to Service Fabric: https://aka.ms/sfguestcontainers -->
<ContainerHost>
<ImageName>proton.azurecr.io/protontesting:latest</ImageName>
</ContainerHost>
</EntryPoint>
<!-- Pass environment variables to your container: -->
<!--
<EnvironmentVariables>
<EnvironmentVariable Name="VariableName" Value="VariableValue"/>
</EnvironmentVariables>
-->
</CodePackage>
<!-- Config package is the contents of the Config directoy under PackageRoot that contains an
independently-updateable and versioned set of custom configuration settings for your service. -->
<ConfigPackage Name="Config" Version="1.0.0" />
<Resources>
<Endpoints>
<!-- This endpoint is used by the communication listener to obtain the port on which to
listen. Please note that if your service is partitioned, this port is shared with
replicas of different partitions that are placed in your code. -->
<Endpoint Name="Proton.TestingTypeEndpoint" Port="8001" />
</Endpoints>
</Resources>
</ServiceManifest>
ApplicationManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<ApplicationManifest ApplicationTypeName="Proton.SFType"
ApplicationTypeVersion="1.0.0"
xmlns="http://schemas.microsoft.com/2011/01/fabric"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<Parameters>
<Parameter Name="Proton.Testing_InstanceCount" DefaultValue="-1" />
</Parameters>
<!-- Import the ServiceManifest from the ServicePackage. The ServiceManifestName and ServiceManifestVersion
should match the Name and Version attributes of the ServiceManifest element defined in the
ServiceManifest.xml file. -->
<ServiceManifestImport>
<ServiceManifestRef ServiceManifestName="Proton.TestingPkg" ServiceManifestVersion="1.0.0" />
<ConfigOverrides />
<Policies>
<ContainerHostPolicies CodePackageRef="Code">
<!-- See https://aka.ms/I7z0p9 for how to encrypt your repository password -->
<RepositoryCredentials AccountName="ProtonCluster" Password="XXX" PasswordEncrypted="false" />
<PortBinding ContainerPort="80" EndpointRef="Proton.TestingTypeEndpoint" />
</ContainerHostPolicies>
</Policies>
</ServiceManifestImport>
<DefaultServices>
<!-- The section below creates instances of service types, when an instance of this
application type is created. You can also create one or more instances of service type using the
ServiceFabric PowerShell module.
The attribute ServiceTypeName below must match the name defined in the imported ServiceManifest.xml file. -->
<Service Name="Proton.Testing" ServicePackageActivationMode="ExclusiveProcess">
<StatelessService ServiceTypeName="Proton.TestingType" InstanceCount="[Proton.Testing_InstanceCount]">
<SingletonPartition />
</StatelessService>
</Service>
</DefaultServices>
</ApplicationManifest>