ESP32 + SD card (Digilent Pmod) only works with very short GND wires?

[sofakng]

I'm testing a project for somebody and it uses an ESP32 DevKitC and a Pmod MicroSD slot.

At first I plugged the ESP32 into the breadboard and then used jumper wires to connect the MicroSD slot but it didn't work. Next I removed the ESP32 from the breadboard and used jumpers to connect directly to the MicroSD slot. It still didn't work.

It was determined that the GND wire needed to be very short and connect directly to the ESP32 for it to work. We tested 40 MHz, 20 MHz, and even 400 kHz but none of them worked with the long (4"+) wires.

Is there any way to have this working with longer wires and/or a breadboard? Can I somehow use capacitors to remove the noise, etc?