Button does not respond when using Calibre Content Server on mobile

[avnermoshkovitz]

I have an ebook with some javascript that I want to view using calibre.
The ebook has a jquery button.
I want to view the ebook on mobile with the Calibre Content Server.

First, I verified that the CalibreContentServer can view the book properly from the desktop - the button responds to clicks, e.g. clicking on the buton opens a dialog - good!
In the desktop (ubuntu 20.04) I use:

• Chrome - version 91.0.4472.114 (Official Build) (64-bit)
• Firefox - version 89.0.2 (64-bit)

A short clip that shows how the button responds to CalibreContentServer in the desktop, can be see in here: https://drive.google.com/file/d/1hff...ew?usp=sharing

Next I moved to CalibreContentServer on mobile.
On the mobile, when clicking on the button in CalibreContentServer it doesn't respond.

In the mobile (Pixel 3, Android 11) I use:

• Chrome - version 91.0.4472.120
• Firefox - version 89.1.1

When I open the ebook via CalibreContentServer in mobile, I can see the button but when I click on the button, nothing happens.

I debug the phone via Chrome devtools (the phone is connected to the desktop (Ubuntu 20.04) via USB cable).
The code gets to add the Event Listener (I can see that, via breakpoint and log message printouts).

resizerEl.addEventListener( 'touchstart', onTouchStartTopDownInitResize, {capture: false, passive: false} );

But when touching the element, the program does not step into the event listener function (onTouchStart) - not ok.
For reference:

• when using the CalibreContentServer on the desktop, the event listener function is trigerred (onMouseDown) - ok
• when using another ebook reader, the program does respond to touching the element (visually, things happen) - ok

My questions:

• what could prevent the touch events from triggering the function?, or
• how to debug the problem further?

Thank you.

[avnermoshkovitz]

A short video clip that shows the problem, and the problematic epub are in:
https://www.mobileread.com/forums/sh...5&postcount=15

Thanks