The confusion comes from the differentiation between total sugars and ‘free sugars’, with only the latter being the kind of sugars we’re told to cut down on. You can see more info here.

The reference intake for total sugars is 90g a day, which includes 30g of "free sugars".

The nutrition info label on food references the total sugars limit of 90g. In this case, the sandwich contains 31.5g of total sugars, which exceeds the limit for free sugars but is only 35% of the total sugar limit, so that’s how it’s labelled.