Hi Jonathan,
If you are programming the host MAC address correctly as suggested by Frank above then a unicast frame should be received. "PN_Receive_Decision_Table" is used only for multicast frames.
Unicast frames will be stored by PRU in QUEPRIO3 and not in QUEPRIO4. Only broadcast frames are received in QUEPRIO4. Are you only picking frames from QUEPRIO4 or you are checking all the four receive queues?
Both the receive ports have to be enabled for receving the frames. Can you check what values are set for four bytes starting from SWITCH_CONTROL_ADDR (0x1E6C) ? Both the upper two bytes (0x1E6E and 0x1E6F) should be having a value of 0x01.
Regards,
Robin Singh