A sticky header relies on JavaScript or CSS continuously tracking scroll position and adjusting the header’s own positioning in response, and when something else on the page also reacts to scroll — a cookie banner, an animation, another fixed element — the two can interfere with each other in ways that show up as jumping, flickering, or the header simply losing its sticky behaviour partway down the page. Because the header sits at the very top of every page, any glitch there is also one of the most visible things a visitor can encounter, even when the actual cause has nothing to do with the header’s own configuration at all.
Watch what else moves when you scroll
Read-only. Scroll slowly down the affected page and watch specifically whether any other element also moves, appears, or disappears at the same moment the header misbehaves — a cookie banner, a back-to-top button, an announcement bar.
Finding another scroll-reactive element timed with the glitch is a strong, specific clue worth having ready before ordering.
It’s also worth noting whether the issue happens consistently every time, or only occasionally, since an intermittent pattern points more toward a timing conflict between scripts than a straightforward configuration mistake.
Sticky header & scroll behaviour repair
Your sticky header jumps, flickers, overlaps content, or stops sticking partway down the page. We isolate the scroll-behaviour conflict and fix it.
- Full backup taken before we start
- If we can’t fix it, you get your money back
- We never ask for your own password
This or something else?
| A sticky header jumps, flickers, overlaps content, or stops sticking on scroll | This fix covers it |
| A mega menu specifically is misaligned, not the header’s sticky behaviour | Mega menu configuration & conflict, a different fix |
| The mobile menu specifically is missing or broken | Menu not displaying or breaking on mobile |
| The whole page layout breaks at a specific screen width, not just the header | Responsive breakpoint repair, a different fix |
| Tabs, accordions, or sliders elsewhere on the page are what’s actually broken | Tab, accordion & slider script errors, a different fix |
What you are seeing
- The header jumping, flickering, or visibly glitching while scrolling
- The header overlapping page content instead of sitting cleanly above it
- Sticky behaviour working near the top of the page but failing further down
- Inconsistent behaviour across different browsers or devices
- The issue appearing after adding a cookie banner, announcement bar, or similar element
Common causes
- A cookie consent banner or announcement bar also reacting to scroll position
- Conflicting CSS position or z-index values between the header and another fixed element
- A caching plugin serving an outdated script version after a header setting change
- JavaScript scroll listeners from two different sources interfering with each other
- A theme update changing how sticky positioning is calculated
What we do
- Reproduce the scroll behaviour and identify every element reacting to scroll on the page
- Determine which specific interaction is causing the header to misbehave
- Resolve the conflicting positioning, z-index, or script interference
- Test scroll behaviour across the full length of representative pages
- Confirm consistent behaviour across the browsers and devices that matter for your visitors
- Check other pages using the same header for the same latent issue
What is included
- The specific scroll-behaviour conflict identified and resolved
- Testing across browsers, devices, and page length to confirm consistent behaviour
- A check for the same issue on other pages using the same header
- The pre-fix backup, kept for 30 days
Not included
- Redesigning the header’s appearance beyond restoring correct sticky behaviour
- Fixing a mega menu’s own layout, which is a separate fix
- Building a new sticky-header feature your theme doesn’t natively support
- Ongoing testing as you add new scroll-reactive elements in future
Questions about this fix
Could a cookie banner really cause this?
Yes, if it's also positioned based on scroll or appears with its own animation, the two behaviours can visibly collide even though neither element was designed with the other in mind.
Will this fix work the same on all browsers?
We test across the browsers that matter for your visitors specifically, since scroll-event timing can behave slightly differently between browser engines.
Does this affect mobile the same way as desktop?
Not always — mobile browsers handle scroll events somewhat differently, so we check both rather than assuming a desktop fix automatically carries over.
Why does the header work fine near the top but fail further down the page?
That pattern often points at a specific trigger point, such as another element appearing or changing state partway down, rather than the sticky behaviour itself being broken from the start.
Could a recent plugin addition have caused this?
Yes, particularly if that plugin adds anything that reacts to scroll, such as a floating button or progress bar, which is exactly the kind of interference we check for.
Related fixes
If this is the second time this year
A bad update breaking the site is a symptom of updates not being tested first. Care plans run every update on a staging clone before it reaches your live site, which is the actual fix for this happening again.
Your access, your rules
Create a separate admin account for us and delete it when we are done. For anything else, we get in touch and agree a method — never a form field on this site, never by reply to an email.
We back up first, always
Before anything is touched we take a full backup and keep it for 30 days. If a fix goes wrong, we put the site back exactly as it was.
If it is not what you bought
If the problem turns out smaller than what you ordered, we refund the difference. If it is bigger, we stop and send a quote before doing any extra work.
If we cannot fix it
You get back what we received. Diagnosis is on us — you only pay when the problem is actually solved. The payment processor takes its fee before the money reaches us, so we never hold it and it is not ours to return. That is true here as everywhere else.
If it comes back
Reply within seven days of delivery and we put it back on the bench at no cost. The fix is not finished until it holds.
What we are responsible for
If something goes wrong with a fix, our responsibility is limited to what you paid for it. We take a full backup first so mistakes can be undone, and we tell you before doing anything outside what you bought.