Why on IOS in a React application, when a component is updated, does it glare (render) something that was not visible initially?

Question

iOS

Why is this happening?
The screenshots show that the part that was not loaded initially glares after returning back (it is simply deleted and re-rendered).

Attached a 59 FPS video to this post so you can see what it's about - https://vk.com/club181964505?w=wall-181964505_1 (or go to osiris.news from your IOS device)
I don't know in my heart why is this happening. Is this a browser issue? Or am I doing something wrong?
The strangest thing about all this is that this does not happen all the time, but every 2-3 times