Issue with MAVLink RC Link on INAV 8 using TBS Crossfire

[tedre191]

I’ve been trying to set up the new MAVLink RC feature in INAV 8.1 with two aircraft, but haven’t been able to get it working.

All documentation I’ve found seems to reference ELRS Crossfire, but I’m using TBS Crossfire modules. Could this be the reason it doesn’t work? Does it even matter?

Here’s what I’ve tried so far:
• Selected the correct UART in INAV and set it to MAVLink.
• Configured the receiver protocol as Serial (MAVLink).
• Set the Crossfire receiver output channels to MAVL RX/TX.
• Enabled RC by MAVLink on the TBS TX side.
• Tried with and without the CLI command highlighted in the documentation too (set mavlink_radio_type = ELRS)

Despite this, I don’t see any RC data coming through INAV. The same setup works fine on both aircraft with ArduPilot; the same connections work with CRSF as the serial protocol on both aircraft as well on INAV.

Question:
Is MAVLink RC supported with TBS Crossfire in INAV 8, or is it only supported with ELRS Crossfire?
If it should work with TBS, what configuration step might I be missing? I'm not running the latest firmware on the TBS side, but close to it (6.36). We'll try to update that too tonight, but the release notes don't mention anything about MAVLINK or INAV.

Thanks in advance for your help!