MathJax does not render after HTMLMath widget is created

[parkey]

HTMLMath: MathJax is not rendered in voila preview or standalone.

This happens if the markdown is loaded after the widget is rendered.
Please see example below.

from ipywidgets import *

b = Button(description='press')
t = HTMLMath()

def click(obj):
    t.value = '$$\int x \, dx$$'
    
b.on_click(click)

VBox((t,b))

When the button is pressed, the latex string shows up in raw format in edit field instead of being rendered as maths.
It works fine, though, in JLab and notebook.