Most probably this issue may not be from theme. Some other external resources may conflict with layer slider.
We need to debug this issue, as we not getting any js error on console window. So could you try some debugging steps given below:
1. Try using WordPress standard theme like 2017, if slider doesn’t appear on this case then issue is not from a theme.
2. After conforming issue is not from a theme you can deactivate individual plugins and check if error exist or not. First try by deactivating live composer plugin..