Issues with Soundcheck Hero Slides

[Putting “Urgent” in your title won’t do anything]

Hi there,
I am re-doing a non profits website and it needs to be done VERY soon.
I am having trouble with the Hero Slides on the Sound check theme. We bought the sound check theme recently and everything is filled in.

HERO SLIDES ISSUES:
Sometimes the slides work fine. On my computer and one other laptop I check it from – there is no issue with the pictures being too large for the slides section.

However,
on different computers the slides are not always centered correctly even though I re-cropped and sized the photos to the correct size length.
Also, sometimes after the photos are going for a bit – they start to no longer be centered at all and will go off to the side and have just black replace the picture.
SO GRATEFUL FOR ANY HELP!
Thanks so much,
Kate