I got really strange issue with Animate CC

I will be grateful for someone to assist me to resolve this strange and annoying issue!

I export HTML from animate CC and it is working fine both for Desktop and a mobile view.

Here is the code:

this.btn.addEventListener("click", doSomething);
function doSomething(e){

}

However, it makes a strange blue highlight color when clicking on the button.
This happens both for Chrome and Edge browsers at mobile view browser (In Real mobile) but not with Firefox...

I attached the files is this link:
http://news.spicygames.com/wp-content/uploads/2020/11/

download and see the FLA please if you want to see by your self how simple is the code...

You can also checkourt this link:
http://news.spicygames.com/wp-content/uploads/2020/11/strange_blue_highlight_on_click.html

and see the blue highlight by clicking on the square at mobile view...

Can someone solve this issue??!