MFE T900 SBAS forwarding

Hardware Pixhawk family
1

Hello guys! I will try to wake an old topic I have MFE T900 Telemetry, ground and onboard station connected to MFE PixPilot.
The idea is to get RC redundancy by connecting two RX:

  1. RX Happymodel EP1 connected by SBAS to ground station T900 to get RC link via telemetry.
    2 The T900 connected to PixPilot to telemetry port and to SBAS port.
  2. RX Happymodel EP1 connected by Serial port to MFE PixPilot.
  3. Ardupilot setup for multiply receivers- RC_Options param 10

The problem is that when I simulate the ground station RX failure ( disconnect RX from ground T900), I lost RC control, but the onboard RX still connected to TX.
My guess is that ground T900 still supply some SBAS information to onboard T900, means no failure identifying by PIX.
But if connect both receivers to PIX by one SBAS and other Serial, everything is working well.

I’m looking forward to your suggestions, guys!