The LG machine is designed to constantly measure load balance, water level & temperature, and will adjust the cycle accordingly. This will include stopping the cycle to rebalance the load by 'oscillating' the drum. This is normal.
Many LG washing machines have large capacity drums, which can be damaged by vibrations if the load is unbalanced. The machines have a special protection device that will stop the machine should it encounter abnormal vibration.
It is possible your machine has detected an unbalance in the load due to the type of flooring (ie wood) or that the different mix of fabrics have unevenly distribuited in the drum. To elininate this from re-occuring we would advise that you ensure the unit is mounted on a solid floor (concrete).
We also advise that you wash full loads ar this is better for reducing vibrations and will prelong the life of the washing machine bearings.
It is also recommended that you seperate the heavy materials (i.e.towels, bath mats and jeans) from light material (i.e. bed sheets, socks, shirts) and perform two seperate washes - as this will help the load to be evenly distributed in the wash.