You cannot have one interface with 192.168.1.1/24 and another with 192.168.1.2/24. You need to create a LAN bridge.https://docs.opnsense.org/manual/how-tos/lan_bridge.html
What are you attempting to do? Is there a reason to use two separate interfaces instead of LAGG, Bridge, or a separate switch?How did you set up the firewall group and rules?