WAN Static IP with birdge mode cable modem need help

[atish]

I have a Opn-sense firewall which is not connecting to internet when connected directly to bridge mode cable modem.

Scenario 1 (not working) 
Cable Modem (bridge mode) --> Opn-sense 2.5.2 CE WAN with Static ip + DNS provided by ISP.
I get gigabit connection between Opn-sense and Modem, but no internet.



Scenario 2 (works)
If I put a linksys router in between
Cable Modem (bridge mode) --> Linksys (Static ip+DNS  provided by ISP) ---->  pPnsense 2.5.2 CE WAN DHCP .
In scenario 2 I get a 10/100 connection with the modem (light shows 10/100), work's

What setup configuration item I am missing on the Pf-Sense to connect it directly with the bridge mode modem


Thanks.

[atish]

I have tried swapping the ports em0 with em1 after doing a factory reset, and that also is not working when connected directly to WAN bridge mode device