Probably need to load the JS at the top of the page.

Just to confirm Steven this is only beta or do you see this on various modes? Is this a new thing or has this always been the case?

There are various things that could be happening - the most likely as Ryan suggests is that the JavaScript hasn't yet run. Alas there is not much we can do about this aside from making the page load as fast as possible as the element needs to exist before it is binded to the navigation. Another is that there is a JavaScript error somewhere preventing it from loading and a third option is that there were some experiments with touch events which might not be triggering for some reason.

Marking as an enhancement - although this is annoying - this could be seen as a useful feature on slow connections. The other option would be to disable the button until JavaScript has loaded which I think is not such a good experience.

I personally think we should focus on making the page load as fast as possible which will also make this problem go away.

swalling wrote:

(In reply to comment #2)

Just to confirm Steven this is only beta or do you see this on various modes?
Is this a new thing or has this always been the case?

There are various things that could be happening - the most likely as Ryan
suggests is that the JavaScript hasn't yet run. Alas there is not much we can
do about this aside from making the page load as fast as possible as the
element needs to exist before it is binded to the navigation. Another is that
there is a JavaScript error somewhere preventing it from loading and a third
option is that there were some experiments with touch events which might not
be
triggering for some reason.

Marking as an enhancement - although this is annoying - this could be seen
as a
useful feature on slow connections. The other option would be to disable the
button until JavaScript has loaded which I think is not such a good
experience.

I personally think we should focus on making the page load as fast as
possible
which will also make this problem go away.

Yes, this problem is likely the loading issue, because it only tends to happen on the first couple mobile pageviews. I have got the error only on Beta, but wouldn't be surprised if it showed up on stable too.

Change 83207 had a related patch set uploaded by JGonera:
Make navigation.js load at the top

https://gerrit.wikimedia.org/r/83207

Change 83561 had a related patch set uploaded by JGonera:
Introduce header-loaded event

https://gerrit.wikimedia.org/r/83561

Change 83561 merged by jenkins-bot:
Introduce header-loaded event

https://gerrit.wikimedia.org/r/83561

Change 83207 merged by jenkins-bot:
Make navigation.js load at the top

https://gerrit.wikimedia.org/r/83207

Closing this since above patch is merged and this is the best we can do for the time being.