One suggestion is to check if there's a pixel or two of gap between menu items. It's possible that my finger tip is flatter and hits more pixels per touch than kerz' or klobag's. 

I haven't been experiencing this, though I'm not much of a landscape user.

Maybe taking a stackshot could help since it seems like the App might be hanging, though I haven't found a way of taking one on an iPhoneX since the home button is gone.

I'm not able to repro either.  I wonder if we need to borrow someone's phone for a bit to debug further.

It does not appear to be device dependent. klobag started with kerz' iPhone X. Then tested on the MTV test iPhone X and get the same result. I tried with the MTV test iPhone X and cannot repro.

One idea is to build a version of Chrome that puts a tint on the background of each menu item cell to help us see if there's a dead zone between menu items. What other instrumentation can we add? I can build a test version for kerz and klobag to try.

See: https://screenshot.googleplex.com/SMQmCGFBxVW

Looks like it's related to the reading list special case menu item.  

Flipping to peterlaurens@, this isn't specific to iPhone X

also may be if you touch and release slow enough (~0.5sec) then touch not registered. If I do the same in Portrait touch is always registering. 
ie Portrait mode: Touch Hold ~1.5sec and release --> Action performed
Landscape mode: Touch Hold ~1sec and release --> No action performed. (Any of the menu items not just Bookmarks)

may or may not be same as what other seeing, but I can show it to Justin in office tomorrow. I don't have non-iPhoneX phones to test the same.

Re #6, when it doesn't register the touch, it also happens on other items. So the observation in #6 maybe what I observed.

Followup: Issue I mentioned in comment#6 is also happening on iOS10.3.3 with iPhone6s in Landscape mode Chrome Version M62. So not anything specific to iPhoneX or iOS11.

Since this reproduces with other menu items, then the reading list badges wouldn't be related. 

Also, since the badges have their hidden property set to YES, they should not be receiving touch events anyway.

From my investigation, I was only able to repro the issue described in #6.

Making bug available for others to pick up.

I can easily reproduce this by tapping slowly on the items in the menu. Happens in both landscape and portrait. TestFlight user reported this on iPhoneSE.

Can we get this prioritized for M66? I'm sure there are lots of folks with hand-eye coordination or reduced fine-motor skills that will have issues with the timing. I'm bumping this back to untriaged to get it back in the system.

Also, can we open this bug to the public, I don't see anything google-specific about it. 

Gautier: Can you take a look at how the Tools menu is implemented. See comment 13.

If you quickly tap and lift your fingers, the menu item is selected.
But if you tap down slowly (and hold it there for say a second or two) then lift, the menu item is not selected.

Assigning to lod@ as you are working on the tools menu.

Removing RVG

I am not sure if this is relevant but I heard from someone in Google a few days ago to whom I sent a video I had prepared of my fingers tapping on my iPhone SE (I did not have the problem on my iPad mini 2.) On the SE I was getting all menu items being non-functional (New Tab, etc.) Whether the SE was in portrait or landscape did not appear to make a difference.

A short while later I received a reply asking me to retest by tapping more quickly on the labels instead of pressing them & the labels started working.

Yeah, that was me :-)