As stated above if SQ326 arrives more or less on time (making the actual connection time at least MCT or above) the OP may face questions if he/she miss the LH flight and rebooking and duty of care becomes relevant. That being said 1 hour is more than sufficient to make it from a B gate to even a remote A gate (unless you walk very slow and the lines at immigration and security check are really long) so I wouldn't worry too much.