Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Microchip Technology/ATSAME51J19A/SDHC0/CC2R#0x0
FSDCLKD=NOEFFECT
Clock Control 2
Force SDCK Disabled
0 (NOEFFECT): No effect
1 (DISABLE): SDCLK can be stopped at any time after DATA transfer.SDCLK enable forcing for 8 SDCLK cycles is disabled
https://github.com/cmsis-svd/cmsis-svd-data