Sticky menu bar

Hello,
I had 2 localhost (wamp) installations of Onepress. The first one was to run tests and the second one to make the successful changes and when was ready to upload it (no code changed).

After the update from “onepress 1.4.3” to “onepress 2.1.0” i have a problem with sticky menu bar. No matter what, both installations will not keep the sticky menu bar. I wanted the menu bar to be visible while scrolling.

What should i do?

Thank you in advance.
lestatinos