So when using Brave or a Chromium based browser the mobile menu works normally but on other browsers that are FireFox based the menu does not stay put if you scroll upwards. It will pull up with a gap not staying at the bottom. Just noticed it because I rarely use those browsers over Brave.
I got the official FF just to make sure it wasn't the other browsers and same thing for me in FF official. So when scrolling up it stays at the bottom but when down it lifts up(I had it backwards). But I noticed it in IronFox and IceRaven. It also happens in DuckDuck browser but for a split second then goes back into its rightful spot.
My phone is a pixel 7 on Graphene OS which is just open source Android with more security.
Here's a picture:
Last edited by NeoMetallix
Yes, tested it here too just to be sure it wasn't some custom CSS causing it.
On Jul 30, 2026, Cedric said:
I've tried several websites and services, browser tools, anything I could get my hands on. But I don't have a Pixel 7. So I can't reproduce myself. I'll keep exploring and see if I can get it reproduced and fixed, but it may take some time I'm afraid.
Weird, you'd think it would be the same on any android phone, but I know they all have their quirks. It's using Android 17 if that helps. I don't think all android phones are on that version yet.
@Cedric I was trying to figure out how to fix this because it did the same thing on my android tablet. I had to ask AI if it could figure it out and it turns out it’s a known bug on Android FireFox.
At this point, the remaining movement is Firefox itself, not your CSS.
Mozilla has an open Firefox for Android bug describing essentially your exact behavior: a
position:fixedbottom element moves when the address bar hides/shows, even though the expected behavior is that it remain perfectly still. Mozilla also has another open bug explaining why a100dvhworkaround still shifts slightly: Firefox changes the layout viewport during the scroll gesture, whereas Chromium generally waits until the gesture ends.
Just fyi. It’s not a FS-related problem.
Thanks. I actually got hold of an Android tablet earlier this week, will have a go at this next week and see if I can workaround.
While it doesn’t fix the problem, this css did help a lot. It still moves up while scrolling up but it will go back to the bottom on its own and stay there rather than remaining elevated until you scroll down.
@media(max-width:767px){
html body.b2 .mobile-tab-bar{
--mobile-bar-height:
calc(58px + env(safe-area-inset-bottom,0px));
display:flex !important;
position:fixed !important;
left:0 !important;
right:0 !important;
bottom:auto !important;
top:
calc(
100dvh -
var(--mobile-bar-height) +
2px
) !important;
width:100% !important;
height:var(--mobile-bar-height) !important;
min-height:var(--mobile-bar-height) !important;
box-sizing:border-box;
z-index:9999 !important;
align-items:stretch;
justify-content:space-around;
overflow:visible;
padding:
5px 4px
calc(9px + env(safe-area-inset-bottom,0px));
transform:none !important;
}
}
@media(max-width:767px){
html body.b2 .mobile-tab-bar::after{
content:"";
position:absolute;
left:0;
right:0;
top:100%;
height:12px;
background:var(--fs-panel-bg,#faf8f2);
z-index:0;
pointer-events:none;
}
}
