It seems we are all having the same issue. If your settings are correct just let it run and it will eventually connect. I screwed around with firmware too. If you have rolled back the firmware, put the latest on at the bottom of bitmain page. Two of mine took every bit of 6 hours to start hashing and have been running 30 hours since with no problem. It's got to be something with the latest batches S9 controller cards. My L3+ can reboot and connect immediately everytime.