They themselves said "..this unreleased version caused issues". That could be referring to anything - including service-overload issues but I don't know why tha

They themselves said "..this unreleased version caused issues". That could be referring to anything - including service-overload issues but I don't know why that would be that surprising. This is exactly why companies like to have tight control of the roll-out of new products. They want to find these types of bottle-necks and glitches in rather controlled environments.