socketcluster: socket hung up error on large messages

I never had this problem before, only appearing after i upgraded from 4.x to 5.0.18.

I’m transferring a large message which fails with socket hung up 1006.

Even dividing up the message into small messages does not work, so long as i try to send them all at once I get the same issue. The problem exists only with my dev osx computer and works fine on my server running ubuntu.

Socketcluster shows

Got error: connect ECONNREFUSED 127.0.0.1:80

And my app shows:

Socket error - SocketProtocolError: Socket hung up
socketCluster CONNECTED
Socket error - SocketProtocolError: Socket hung up
socketCluster CONNECTED
Socket error - SocketProtocolError: Socket hung up
socketCluster CONNECTED

Maybe it’s a thing in uws?

Edit: Another difference is that the server is running https while the localhost is unsecured.