Image Carousel not rendering correctly on iOS

I have been having an issue with using a carousel to show 5 or so images within a WordPress page.
I have tried quite a few plugins which work on Desktop (Chrome, Firefox on Ubuntu/Windows & Mac), mobile /tablet (Android) but when viewed on the customers iOS both phone and iPad the slideshow doesn't work properly. (I don't have iOS device so cannot test). Sometimes it just doesn't load, other times it only renders half an image.

I am using bootstrap so have tried straight BS markup, and also various plugins. But issue keeps coming back.

A solution would be great but just a way forward with troubleshooting would help.