I used these GPIO pins to drive the Explorer display with a pure MicroPython driver and it works perfectly.
BL = 13 # Pins used for Pimoroni Pico Display
DC = 16
RST = 12
MOSI = 19
SCK = 18
CS = 17
You can find the rest of the code here:
Pico explorer display with Microptyhon - Support - Pimoroni Buccaneers
I hope this helps