Why can a block disappear in Safari (Mac only)?

Question

css

Good day. Please tell me the solution to the following problem. There is such a thing as maniaco.convilla.com.ua . If you go from under the safari from a poppy, then this is what happens: at first everything opens fine joxi.ru/j1A5l4ViK7Dp2E But if you scroll up / down and return to the main slide, the phone in the lower right corner is no longer displayed joxi.ru/el2ZJBpt8QzG2JAt first I thought that the block with the phone was leaving the screen. But if you look in the element manager, you can see that it is in its place. Moreover, if when the phone disappeared, hover over the menu on the right, and then move it away, the block with the phone appears (although in fact no actions were taken. It seems that just at the moment of flipping through the slides, the browser is buggy and it does not render the block with the phone. Moreover, this feature only manifests itself in safari under poppy. Please tell me that this can be a solution. Ato, I have already broken my head. It is very necessary) I will be grateful for any help)))