ADcmXL3021 same data from all three axes

We are using the ADcmXL3021 with the Teensy 4.1 microcontroller. We are currently reading the X_BUF, Y_BUF and Z_BUF registers with the following setup:

- SPI clock speed is set to 13MHz 

- Operating Mode: MFFT (also tried MTC)

- Window Setting: Hanning

- No decimation, No FIRs, No Null corrections

- No FFT averaging

To achieve the above settings, we set the following registers:

- REC_CTRL = 0x1100

- AVG_CNT = 0x0001

- FFT_AVG1 = 0x0101

FFT_AVG2 = 0x0101

FILT_CTRL = 0x0002

We get the exact same results for all three axes, for MTC mode and MFFT mode. Has anybody experienced this before?