server-sent event streaming from node - truncated data

**Describe the bug**

I have node a serverless function that returns content-type text/event-stream. Messages are delimited by two newlines. The final message is a raw text line:

data: [DONE]

1. When I run in postman against localhost I see the raw response is

``` text
id: ..
data: ...

id: Thu Jun 23 2022
data: [DONE]
```

1. When I run in postman against the PR build endpoint raw response is only one line
`data: [DONE]`

I am guessing this might be because I'm running node out of process instead of c# in process. Last time I tried to stream binary data from node in a serverless function, I had to load it all into memory and then send it out the response. Do you think this issue with SSE / server-sent events is the same class of problem?

Can this work without changing architecture to SignalR or using c# ? Really liking Nuxt3 on swa.