Thank you Dan,
If possible, please share the schematic and gerbers for your carrier board, so we can check the SPI connections. If you can’t share, please check you have all the POCI=CIPO=MISO signals connected together; and all the PICO=COPI=MOSI signals.
For SPI, you need to make sure that each device on the bus is powered and has its chip select pin pulled high. If a device is off, or its chip select is left to float, or - worse - the chip select is low, you will get data corruption. Communication may be impossible.
Please check that you are pulling the correct pin high for the SD chip select. On the ESP32 S2, “A5” is GPIO 5. Is that correct? If you share your schematic and gerbers, we can check.
Also, do be careful with your SPI modes. We have talked previously about SPI modes here.
I hope this helps,
Paul