The font is updated in theme settings and it is listing poppins-regular, but not applied to whole content.
We will try to deactivate plugins one by one for checking and update you , but certain css (font class) is updated from the following files,
/wp-content/uploads/xstore/kirki-styles.css
/wp-content/uploads/xstore/m8Hgx.css
can you share how could we reset values from these 2 files?