How do I correctly increase the variable Size in my Azure Logic App?

I'm facing an issue with my Azure Logic App where by an "Append to Variable" action returns the following error:

The variable 'ResponsesString' has size of more than '105018915' bytes. This exceeded the maximum size '104857600' configured. Please see https://docs.microsoft.com/en-us/azure/logic-apps/edit-app-settings-host-settings#variables for updating the maximum configured value.

I have edited my host.json file as follows:

{
  "version": "2.0",
  "extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle.Workflows",
    "version": "[1.*, 2.0.0)"
  },
  "extensions": {
    "workflow": {
        "Runtime.Backend.VariableOperation.MaximumVariableSize":"209715200"
    }
  }
}

I have then restarted the Logic App, but I still get the same issue. Just to add the variable is inside a for loop.

When you configure host settings for the Logic App, the variable size setting must be nested under the settings node within the workflow extension.

Your original configuration Runtime.Backend.VariableOperation.MaximumVariableSize property directly under workflow, so it was not picked up by the runtime.

host.json:

{
  "version": "2.0",
  "extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle.Workflows",
    "version": "[1.*, 2.0.0)"
  },
  "extensions": {
    "workflow": {
        "settings": {
        "Runtime.Backend.VariableOperation.MaximumVariableSize":"209715200"
        }
    }
  }
}