Mac M1 Sonoma: Cannot read my 256Gb Micro SD card

I have a brand new 256Gb SanDisk Micro SD card and I'm not being able to read/use in my Mac through the internal SD Card reader slot (I don't have an external card reader to try this option). The card was working at the very beginning, but after a format (or something I don't remember) it become not recognized by SO. I've tried "Disk Utility" format (Erase) with all partition types (ExtFAT, Mac OS Extended, etc) to no avail. It formats the card successfully, but then it is still unseen by "Finder". I've also tried "First Aid" in "Disk Utility" to no avail too, it does the recovery with no errors, but the card continue to be unseen, so I cannot write to it. I've been reading How to fix broken GPT, GUID and unmountable, no type volumes? , but I'm currently stuck. If I do (in Terminal): sudo gpt -v show /dev/disk4 The response is: gpt show: /dev/disk4: mediasize=255869321216; sectorsize=512; blocks=499744768 start size index contents 0 1 MBR 1 65535 65536 499679232 1 MBR part 7 Any help in order to make my SD Card to be recognized/work? I'd prefer to use ExtFAT so it can then be read in Windows as well as in my Android mobile. Edit 1: After @David Anderson suggestion. diskutil erasedisk exfat MyExFAT mbr disk4 Started erase on disk4 Unmounting disk Creating the partition map Waiting for partitions to activate Formatting disk4s1 as ExFAT with name MyExFAT Reformatting existing ExFAT volume Volume name : MyExFAT Partition offset : 65536 sectors (33554432 bytes) Volume size : 499679232 sectors (255835766784 bytes) Bytes per sector : 512 Bytes per cluster: 262144 FAT offset : 32768 sectors (16777216 bytes) # FAT sectors : 7680 Number of FATs : 1 Cluster offset : 65536 sectors (33554432 bytes) # Clusters : 975808 Volume Serial # : 6ab00ea2 Bitmap start : 2 Bitmap file size : 121976 Upcase start : 3 Upcase file size : 5836 Root start : 4 Mounting disk Could not mount disk4s1 after erase Finished erase on disk4