Hello.
Our theme has the next places for the Typography:
1) Theme Options > Typography. It controls the Body font and Headings font-family. All the elements on the site inherit these fonts if other is not changed in the personal element settings.
2) Theme Options > Header builder. And there are a few places to change the font of the header or menu elements if you need that or keep default settings and then body font will be used.
XStore supports Elementor Typography settings for the headings and if you inspect the element you’ll see that it uses the Elementor settings https://prnt.sc/26j1kdd
So, what exactly does not work for you? Provide screenshot of the element that displays the wrong font and we’ll inspect that.
You can use Elementor experiment settings. The only option that could make a problem is CSS optimization. Sometimes it causes style issue for the mobile version of the static blocks. So, you can try to enabled and check. If everything is ok then keep it enabled. In case you have style issues then it would be better to disable that.
Regards