Hello,
The Jump is due to the Logo Height/Menu Paddings being set using JS and has already been mentioned in the Documentations: http://docs.semicolonweb.com/docs/header/header-heights/#docs-steps-using-javascript .
To resolve this issue, we highly recommend using the following CSS:
/* Custom Header Size
-----------------------------------------------------------------*/
.header-size-custom #logo img {
height: 40px;
}
@media (min-width: 992px) {
.header-size-custom #logo img {
height: 50px;
}
.header-size-custom .header-wrap-clone {
height: 90px;
}
#header.header-size-custom + .include-header {
margin-top: calc( -90px - 1px );
}
.header-size-custom.sticky-header-shrink #header-wrap #logo img {
height: 50px;
}
.header-size-custom .menu-container > .menu-item > .menu-link {
padding-top: 34px;
padding-bottom: 34px;
}
.header-size-custom.sticky-header-shrink .menu-container > .menu-item > .menu-link {
padding-top: 34px;
padding-bottom: 34px;
}
}
Then simply add the .header-size-custom Class to the #header Tag.
This will definitely work fine. Hope this Helps!
Let us know if we can help you with anything else or if you find any further issues.