I REALLY think there is a manufacturing defect with the batch that i have i got three round displays in the same shipment and only opened one and kept the other two for safe keeping… i just opened the second box and got the same effect. I can run the sketch on XIAOSAMD and Expansion board and sd card and no problems but put the same in the round and no go… so i dont think their can be any software reason… it has to be hardware… only thing i can think to do is try to test probe from the sd card back to the XIAO header pins, but i dont have good enough eyesight for that