Feature Slider Image Size

I have 5 images in the slider on this page: https://rmofblainelake434.ca/ They are all the same size...1920px x 820px ....as the slider panel suggests, but they are jumping between 3 different image heights. I saved them all for web via the same process, using the same size. Why does this happen? How can the slider be made to show them all the same?