Event handler not called when clicking on icon inside button

Greetings Experts,

Background:
ASP.NET 4.6.1
C#
Material-Components-Web (to add Material Design to page)


I'm trying to use Material-Components-Web in an ASP.NET Forms project. The following code shows an icon inside a button.

<button type="submit" name="ctl00$maincontent$btnRefresh" id="maincontent_btnRefresh" class="mdc-fab mdc-fab--mini lexbe-fab">
        <i class="material-icons"> refresh</i>
</button>

protected void btnRefresh_Click(object sender, System.EventArgs e)
{
       // Called.
}

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If I click near the edge of the button it works and the event handler in code behind gets called.
However, if I click directly on the icon, then the even handler is not called.

Question: What's the right way to get the button to call the event handler even if it is the child icon that is clicked?

Thanks!