Sdmmc microsd card doesn't work on JetPack 4.5.1 & 4.6

Autonomous Machines Jetson & Embedded Systems Jetson Xavier NX
4

You can refer to this post.

Actually, the most important things are: cd-gpios and vmmc-supply. These two should match your hardware design.

Even if your give a always-on vdd, you have to assign a always-on regulator to the vmmc-supply.