checkbox compiled returning error

Hi everyone,

with this checkbox: [checkbox domanda-1 use_label_element “FINESTRE” “SISTEMI SCORREVOLI” “SISTEMI OSCURANTI” “PORTE DI INGRESSO”], even with all data checked the field returns an error (every checkbox is hidden and wrapped into a icon).
I provide again the page link: https://qfortticino.ch/qfort-ticino/qfort-svizzera/

Thanks to everybody for any help provided

Roberto

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