Mercury with multiple receivers not showing OK

  • Hello, I'm using a Mercury powerbox with two Futaba receivers connected. RX 1 is a Futaba R6308SBT and RX2 is a Futaba R6303SB.

    RX 1 shows as OK on the display while RX 2 shows FS in display. There are no antenna fades counting and if I pull out RX 1 then RX 2 becomes OK and RX 1 FS. I was expecting to see both receivers to be showing OK during normal operation. Is this normal behaviour?