How to optimize a jumping slider?

Question

css

The site has a slick slider. When loading the page, respectively, the script does not have time to initialize the slider and the page is twitchy, then this block is huge, then, accordingly, after initialization it returns to normal. Is there a way to remove this intermittent appearance?
ps So far, either a preloader on the page comes to mind (but the customer is in no hurry to do this) or set the height at different resolutions and hide everything behind the container (but the method is so-so).

Answer 1

I do this: I do the parent of the slides display: flex; slides opacity: 0; when the slick is loaded and the slider is initialized, it adds a class to the parent, through it I remove the opacity of the slides and voila)
PS: and now you can make the parent a preloader background