I'm trying to use a REST API I built, but I cannot handle HTTP error codes in-game, because attempting to iterate over the request handle throws the following error: Server returned HTTP response code: 400 for URL: ..., and getmetatable(handle).__index.response() simply returns nil so I am unable to check for certain response codes there either.

I believe this issue was said to be fixed here #3398. However, in the latest version, this bug is still here. I am tempted to look at the differences between the relevant files in the latest release and in the older ones to see what's going on.

I am now using https://http.codes/ for testing purposes, and I can confirm that I can correctly get codes for responses like 200 OK. But with 400, 404, ... I only get nil, and an error if I try to read the response.
Thank you in advance for your support!