Responsive Carousel does not work with browsers: Chrome, Opera and Vivaldi

The hight stays at real picture hight.

• Operating system and version (macOS Sierra 10.12.3 and Windows 10.0)
• Browser and version (Google Chrome 56.0.2924.87, Opera 43.0.2442.806 and Vivaldi 1.7.735.46)

Here is a demo of the problem (desktops with i.a. Chrome & Opera all stable) on JSFiddle:
https://jsfiddle.net/josmaissan/2e54sbt7/

This is what it looks like:

Here are some posible solutions:

1. Solution option 1, with the suggestion of @Jas-n:
   https://jsfiddle.net/josmaissan/vgh5z4zx/
2. Solution option 2, with the suggestion of @DeltaOS2:
   https://jsfiddle.net/josmaissan/0tqjxrf3/
3. Solution option 3, Prevent images in carousel-item to be stretched #21799, with the suggestion of @vanduynslagerp:
   https://jsfiddle.net/josmaissan/08u40Lue/