My personal Pixelbook is affected by this issue (version 71.0.3572.0, 64-bit)

To reproduce, swipe with two fingers on the touchpad with a bit of "throw". Instead of kinetic scrolling being a smooth extension of the swipe, there is a short pause in scrolling right after you lift fingers off the touchpad before kinetic scrolling resumes.

The effect is very jarring and unpleasant. Can the priority be increased?

Same here on my Pixelbook on version 70.0.3538.76. Start scrolling with two-fingers on the touchpad, then let go. Instead of continuing smooth kinetic scrolling, first it completely stops scrolling for a split second, then suddenly resumes and finishes the kinetic scroll.

The effect can be observed right in the Chrome browser.

Android apps don't show this, but there scrolling is sometimes laggy, i.e. there is a significant delay between my fingers moving over the touchpad and the app actually scrolling the content. Kind of like when you're trying to remote-control a mouse pointer over a slow internet connection; it always lags behind.

Exactly the same behavior here. Sudden stop of scrolling and then it resumes. This only appears when scrolling using the touchpad. When I use the touchscreen for scrolling everything is perfectly smooth.

zsoltvasvari@ Is it possible for you to try Chrome Canary or Dev? There have been a few fixes related to scrolling/flinging recently. If the issue is still reproducable on ToT/Canary/dev would you please capture a chrome trace using https://www.chromium.org/developers/how-tos/submitting-a-performance-bug

afakhry@ do you know how will be the proper owner for this issue?

Increasing the priority since more people are seeing the issue.

bleung@ can you please triage this?

I receive the same problem on my Pixelbook 
[Version 70.0.3538.76 (Official Build) (64-bit)]

When scrolling on a web page using two fingers its like the scroll is exaggerated like it accelerates then when I stop there is a small pause and a "hop" of the page if I scroll using the touchscreen this doesn't occur, but using the trackpad it happens every time. the only way for it to not do it is if I go extremely slow with two finger scroll and really focus on letting go of both fingers at exactly the same time.. [and that only seems to improve the experience 10% of the time] 

Unfortunately this additional bounce / hop at the end of a scroll has gotten to be something I see each time I try to scroll a page so now i'm alternating between using the trackpad to click and touch screen to scroll. [which is not something I want to commit to muscle memory]

Adlr@ can you route this to who worked on the Eve touchpad?

I have same problem, super bummed, borrowed a Pixelbook for few days in October, convinced me to buy one, amazing tackpad, perfect weight and size, screen ration, etc. Now I buy one, was using for an hour, amazing. Then this big update and its bad, scrooling is a pain, and fine mouse control is an issue. Also why cant I have a 4 digit pin to unlock my Pixelbook. 

Have upgraded my Pixelbook to Version 72.0.3611.0 (Official Build) dev (64-bit)
and am seeing the same problem now. Was working fine in previous versions...

Only seems to happen when I'm scrolling with two-fingers on the touchpad. It will freeze to input, sometimes for some seconds, and then start working again.

Can confirm this happens on the beta, dev and canary channels with my pixelbook. The later 2 are far worse than the beta channel as it will just completely stop in the middle of scrolling. This should be getting more attention for how badly it impacts the flagship chromebook.

Just to make sure that this doesn't get missed for M71...

I don't think it's known yet whether the problem is in firmware, Blink, or somewhere in between.

It's been a while since this was updated; Stable is around the corner.  Any updates?  Really a RBS for M71 since this isn't a M71 regression?

I'm seeing this too on the current dev channel. It looks like:

(1) It only affects the touchpad, scroll with the touchscreen is extremely smooth;
(2) It affects Android apps, so it doesn't seem likely to be a blink issue.

This is still happening after upgrading my Pixelbook to Version 72.0.3623.3 (Official Build) dev (64-bit), from Version 72.0.3611.0 (Official Build) dev (64-bit).

derat@, I understand in #24, but this isn't a M71 regression so I'm not going to block 71 on it.  That shouldn't stop it from being prioritized, however.

adlr@, per conversation yesterday, after experimenting more on eve 70.0.3538.110 / 11021.81.0, I don't think that this is tied to hover. The pauses that I'm seeing when flinging on a long page still vary, but they don't seem to be tied to whether my fingers are hovering or not after the fling.

Still happening after upgrading to Version 72.0.3626.8 (Official Build) dev (64-bit), from Version 72.0.3623.3 (Official Build) dev (64-bit).

Really frustrating, with touchpad sometimes not responding for several seconds at a time, when trying to use two finger scroll to move up or down pages in Chrome.

If I scroll using the arrow keys touchpad will become responsive again...

#24: The touchpad stopping working entirely on M72 is a separate problem tracked by  issue 911334 . Please star that issue if you want updates (it looks like it was hopefully just fixed).

#25: Thanks derat! The issue you pointed out is exactly the one I'm seeing. I've starred it now. I was mixing this up with stuttering, that I am also experiencing with web content.

Keeping my fingers crossed that the next update will get this fixed. Really bad user experience right now, as you well say...

My two pixelbook on 73 and 72 both have this issue.

Judging from the feedback from users, it looks very likely to be a firmware regression.

Can't we try to bisect the firmware binaries to see when the regression happened ?

Seems to be fixed now in Version 72.0.3626.15 (Official Build) dev (64-bit), as per my comments in the thread related to  issue 911334 ?

#28: I don't think so. I still see it on 73.0.3638.0.

I can confirm I still see the problem in 72.0.3626.15.

Still present on 72.0.3626.15 for me.

shecky mind to take a look?

I'm having the same issue. I noticed this behavior on the floor models of Best Buy last night, but took a leap of faith. I was highly satisfied with the trackpad two finger swiping all night.

Come this morning, there was an update that included trackpad firmware update... now it is stuttering like the floor models at Best By did.  

NOT HAPPY!  If this isn't resolved soon I will just take my pixelbook back and avoid chromeOS for a few more years...

Yes I am aware of this issue for a while, just haven't got time to fix it. I have checked if this is due to new touchpad firmwares but I have found the issue to be reproducible even with older ones. I currently suspect if this is due to a gesture library change or something else but I need more time to investigate.

For the record, I can't observe the same issue on other devices.

Please fix this bug soon. Please.

This bug is discussed in a reddit thread: https://www.reddit.com/r/PixelBook/comments/9zgree/weird_jitter_when_scrolling/

I've located the CL that caused the problem. Will look for a fix.

I'm having this issue also with a Pixelbook I bought a few weeks ago along with some other issues with the track pad. When I use a USB-C to Ethernet adapter plugged into either USB port, the track pad stops working all together. I've tried two different adapters with the same results. What is the status of this issue please. Thanks. 

Thanks for your patience and sorry for the bad feeling.

We are discussing internally to figure out the best solution for this regression.

As for the type-c adapter issue you have mentioned, I don't actually recall any similar one in the past. Could you file a feedback report and cc me (sheckylin@) and adlr@? 

Thanks again!

We have figured out a solution for this. Will implement soon.