Fix WP Live Font Mismatch

My site’s typography behaves oddly: the fonts I set in WPBakery look ok when editing yet on the live pages they either jump to something else or refuse to change at all or all go bold. The discrepancy is identical in Chrome, Firefox, Safari, and Edge, and it persists even after a full cache-and-cookie purge on every machine I’ve tested.

I need someone who can trace the problem—whether it’s a stray CSS rule, a theme override, a plugin conflict, or something buried in the WordPress customizer—and apply a clean, permanent fix. Please investigate directly in the theme files or child theme, review any inline styles WPBakery may inject, and make sure the rendered front-end matches the font settings I choose in the builder.

Deliverables
• Corrected CSS or theme adjustments that keep editor and live views in sync
• Brief note explaining what caused the mismatch and how you resolved it

I’ll provide admin and FTP access immediately so you can start.

Also cannot add new user to wordpress.
Also fault codes displaying:

Notice: Function WP_Scripts::localize was called incorrectly. The $l10n parameter must be an array. To pass arbitrary data to scripts, use the wp_add_inline_script() function instead. Please see Debugging in WordPress for more information. (This message was added in version 5.7.0.) in /home/u310697456/domains/airconditioning-london.co.uk/public_html/wp-includes/functions.php on line 6131

Notice: Function WP_Scripts::localize was called incorrectly. The $l10n parameter must be an array. To pass arbitrary data to scripts, use the wp_add_inline_script() function instead. Please see Debugging in WordPress for more information. (This message was added in version 5.7.0.) in /home/u310697456/domains/airconditioning-london.co.uk/public_html/wp-includes/functions.php on line 6131