"jumping images" on website upload

Hello! Love your theme and use it in all my website with elementor pro. :)

The problem:
when opening the website there is a "jump" with the size of the images, you will see it if you will open the link immediatly.

I have this problem with 3 new website:
http://innocanpharma.com/
https://ride.vision/home/
http://virucure.com/home/

Please, Do you have any advice?

Thank you!