Would you be able to confirm your firewall settings to permit UDP traffic on 319 and 320? If possible capture the PTP packets with tcpdump $ sudo tcpdump -i dst port 319 or dst port 320 [-w <filename.pcap>]
Also confirm the ptp4l.conf details as to whether it is set up for default or gptp.
I am working an issue now where the default profile only works with the firewall turned off.