Just noticed something interesting that definitely wasn’t happening earlier today:
When my scroll amount reaches the bottom of the page (100%), everything starts bouncing. Scrolling back up to ~96% or so fixes it.
I’m using Windows 10 Education 21H2, AMD Ryzen 5 5600X, and Chrome 101.0.4951.67
The bug does not exist on edge, are you sure it is not yet another example of the move fast, break things crap that Google likes to do as they turn their users into beta testers?
It very probably is a Chrome bug, good to know it’s not happening on Edge 
Nope. Not for me.
Windows 10.
Chrome: Version 101.0.4951.67 (Official Build) (64-bit)
Interesting 
guess it’s just me then 
Your are not alone!
I am having this problem sometimes and I am on linux with firefox.
I thought it was me too
This thread is bouncing up and down as I am writing!
Ah… the plot thickens! Interesting that we don’t have the browser or OS in common What GPU do you have?
Old Nvidia GeForce GTX 650 Ti 
I was thinking it might be my mouse dying.
It is not constant just comes and goes.
Vivaldi (5.2.26… ) on Linux: no problems (quick test Firefox…95…, older Opera 67.0.35… no problems )
Hmm, I’m on Linux/Firefox right now too and do not have this issue. I wonder if this happens on specific screen/window sizes?
It definitely doesn’t seem wide spread, as it’s just me and @DNorman so far I was seeing it both on a 27” and a 32” inch monitor, both 1920x1080, one Dell, one LG. I saw it once when the window was full screen and once when it was ~900 pixels wide. I’m not seeing it again today though, at least at so far
Also happens to me, intermittently (and not so much recently). Just thought it was related to the adds as generally when I noticed the glitch the same adds would be displayed. 
(I generally have my browser in windowed mode and window-size didn’t seem to matter)
Oh that’s an interesting angle- I have adblocker turned on so I don’t see any ads except the site banners (I’m a Patreon supporter so it’s ok 
), but I guess if you’re seeing ads, it’s not an adblocker thing? Just to check, what’s your OS, browser, screen size, and GPU?
Same as calpgrmr’s, 10-series NVidia, HD monitor. Never have the browser in full-screen though, so doubt that GPU/Screen-size matters - the glitch has all the hallmarks of CSS misbehaving.
I figured it out- or at least the cause- there’s some JavaScript that’s causing this line:
to update itself about 10 times a second, constantly. It looks like the JS is assigning those classes over and over again instead of just once.
I have found it when scrolling through the NEW POST feed and believe it is the NEWER POST being added as you are scrolling…but never as @joseph gif was showing…Win 10 viewing BA at 80% scale. Very old AMD FX-6300 Hex Core
Chrome Version 101.0.4951.67 (Official Build) (64-bit)
Windows 10 Version 20H2 x64 KB5013624
Does not happen for me
The bug oddly does not happen to me as well in latest Firefox & MS Edge:
OS: Windows 11 Home
GPU: NVIDIA GeForce RTX 3050 Ti Laptop GPU
CPU: 11th Gen Intel(R) Core(TM) i7-11800H @ 2.30GHz 2.30 GHz (8 cores)
I have seen that before. Ctrl+F5 might help. Or maybe you got opted into receiving a newer version of something. That’s done without notifying anyone in all sorts of software and websites all the time these days, which greatly increases the “works on my machine”-phenomenon.
It happens for me all the time, on mobile devices, ios and android. It has to do with ads.