STM32H735-DK Audio recording from codec WM8994 always capture zero value.

[IDe P.2]

I have a STM32H735-DK and I'm trying to get an audio data from codec WM8994. I programmed the SAI1-A to be SLAVE_RX while SAI1-B is MASTER_TX. I programmed the codec input INL1. Everithing seems to be fine, the DMA fifohalffull and fifofull are generated but audio samples are always zero. can you give me some suggestions?

[Bowman32]

Please refer to SAI audio play example provided in STM32CubeH7 firmware via this path: STM32Cube_FW_H7_V1.9.1\Projects\STM32H735G-DK\Examples\SAI\SAI_AudioPlay