Sticky navigation extending bellow static navigation after update

Hi,
I recently updated to version 1.11.1 and my sticky navigation started to behave strangely in the first steps of scrolling down. When scrolling down, it appears a bar the size of the navigation bellow the actual navigation and it disappears the more I scroll down.
I did the update on my staging website before doing it on my main website and this happens only on the staging where I did the update. I guess something got broken after the update. In my staging website, I have to cache plugins and I have deleted the browser cache several times to see the same result.

Thanks in advance.