Why fixed menu jerks when scrolling bootstrap 3?

Question

css

Why fixed menu jerks on page scroll, bootstrap 3?
Not all the time, in some places.
Who could have this?
z-index of other elements can influence?
Thank you.

Answer 1

Anything can affect. Even if only a clean bootstrap is just connected, it can still twitch, depending on the installed applications, running applications, installed browser extensions, the browser itself and even flashes in the sun can affect and twitch the menu.
We need to understand, and not ask general questions, like "My leg turned up today when I was walking. Who had this? Can the unevenness of the road or my feet affect this?".