cannot mount Sandisk External SSD Extreme - APFS error 49218

After a reboot I am unable to mount an external USB-C SSD with Catalina 10.15.5 Disk Utility is recognizing the disk, I can see a "**disk3**" container with my APFS volume , but once I try to activate it I get a *com.apple.DiskManagement.disenter error 49218* When trying a diskutil repair I get : Started file system repair on disk3s1 1TB - SSD Repairing file system Volume is already unmounted Performing fsck_apfs -y -x /dev/rdisk3s1 Checking the container superblock Checking the space manager error: (oid 0xa550) cib: invalid o_cksum (0x0) error: failed to read spaceman cib 0xa550 Space manager is invalid The volume /dev/rdisk3s1 could not be verified completely File system check exit code is 0 Restoring the original state found as unmounted Finished file system repair on disk3s1 1TB - SSD But disk still cannot be activated afterwards. I already tried disk utility from recovery mode, no success... Also tried to connect the disk with another USB-C cable with no success... The disk is 4 months old and worked initially. What are my data recovery options?