File system already mounted - slot init failed (0x103) - wav recorder

[learex]

I'm using a AC101 type DevBoard 2.2 and I'm trying to get the recording to work.
ESP-IDF Release v4.4.2 and this example: pipeline_wav_sdcard

E (388) vfs_fat_sdmmc: slot init failed (0x103).
E (388) SDCARD: File system already mounted

Is the error message. I didn't find any entries similar. Am I overlooking something?
I tried tracing and I got to a very low level but now I'm completely stuck:

record_wav_sdcard_example.c #44 -> board.c #95 -> esp_peripherals.c #347 -> audio_thread.c #76 -> tasks.c

app_main -> audio_board_sdcard_init -> esp_periph_start -> audio_thread_create -> xTaskCreatePinnedToCore

Did anyone else encounter the same problem and can help me?