I have updated a Taranis X9D+ with the latest firmware (2.3.5) I have also a X8R receiver.
After updating the firmware using software Companion, TX and RX don’t bind anymore.
I have tried to update the firmware for the internal and external module using the one provided by FRSKY: https://www.frsky-rc.com/x8r/.
For the internal and external Module I have tried both the combination LBT - LBT and FCC - FCC.
but no one works.