Hello,
I have checked your site, and the product title font is currently controlled by custom CSS that sets it to Times New Roman:
html .wd-product .wd-entities-title a {
font-family: "'Times New Roman', Times, serif", Arial, Helvetica, sans-serif;
font-size: 15px;
}
This means the font change you are seeing is due to the applied CSS, not the theme update.
If you would like to change the font, you can do so directly from:
Theme Settings > Typography > Advanced Typography: https://postimg.cc/nsRS14Rx
Best Regards,