I purchased an Iflight Extended Combo set with 6212 motors with encoders and the Iflight extended board (which has an internal IMU).
When I first plugged the board in, both the external and internal IMU's were displaying data. I updated the board to the 2.63 firmware and now the internal IMU doesn't show any readings. I tried the other 2 newest firmware options and neither of them make the Internal IMU work.