CRAZYBEEF4FS SPI RX doesn't support 16 channel AFHDS 2A

Describe the bug

Failsafe cahnnel values when binding SPI RX to Multiprotocol FlSky2A 16ch mode. The failing configuration is CRAZYBEEF4FS running v2026.6.2 and multiprotocol FW v1.3.4.63. Last working configuration is CRAZYBEEF4FS running v2026.6.2 and multiprotocol FW v1.3.4.31. My quadcopter is a Mobula 6 FlySky option.

Binding works and transmitter gets telemetry but Betaflight Configurator Receiver tab shows "Failsafe active" and all Rx channels show failsafe values.

To Reproduce

flash Multiprotocol module with FW v1.3.4.63 and bind to a CRAZYBEEF4FS. Check Receiver tab in Betaflight Configurator

Expected behavior

after succesfull binding all Rx channels should display reasonable values according to Tx

Support ID

a7e23a04-ca82-4b0a-9a69-4acf6d6484eb

Flight controller

AIO flight controller which comes with Mobula 6 FlySky Rx option from 2019

Other components

stock Mobula 6

How are the different components wired up (including port information)

stock Mobula 6

Add any other context about the problem that you think might be relevant here

there is a multiprotocol bug report on that topic: https://github.com/pascallanger/DIY-Multiprotocol-TX-Module/issues/1178 Pascal suggests to fix this in Betaflight.

I have a working fix (implemented by copilot - sorry...): https://github.com/FelixSchreiber/betaflight/tree/fix_16ch_FlySky2A