Well, it seems to be that the UUID of /dev/sdb3 and /dev/sda3 is identical... I have the same issue here, but no solution. Anyone ?...
/dev/sda3: UUID="dba517ac-98f7-95b9-1f51-fb8978ee93fe" TYPE="linux_raid_member"
/dev/sdb3: UUID="dba517ac-98f7-95b9-1f51-fb8978ee93fe" TYPE="linux_raid_member"...