SocketStream write error : 1 60

I have signed up to try out the HiveMQ broker. The broker is having problems holding on to the connected clients once I start publishing raw data ~2Mb in size. My logs are showing SocketStream write error : 1 60 which appears to be a time out of some kind after sending 1-8 packets.

I have no problems publishing data to my local EMQx broker with no TLS or authentication, but I wanted to see how my application behaves in the outside world.

Does anyone have any ideas what is happening?