I can fully confirm the issue is due to flow control or lack of in my code the system runs out of resources and this is when it errors, I have implemented flow control in my protocol and it now works without errors. One thing I did find is that the documentation on flow control was lacking but luckily I found this post which makes implementation clearer https://medium.com/@pgjones/an-asyncio-socket-tutorial-5e6f3308b8b0

I am not sure if you would still classify this as a bug the error could be clearer but it could be expected behaviour when you run out of resources, I think this can now be closed I am just unsure of the etiquette as to who closes it and what resolution should be selected.