PUB/SUB with bind on subscriber side not working on version 3.2

test_zmq.py freezes on 0mq version 3.2.3 whereas it works fine on version 2.2.0
Increasing the sleep duration doesn't seem to help.
It works if the PUB socket issues the bind.

In test_zmq2.py the SUB finally catches the message after dropping the first n. (n varies from 90 to 12000 in my case).