An observation that an end-user may make is that a COMBOBOX in a CONSTRUCT allows the user to select multiple values, whilst a COMBOBOX in an INPUT, only one value can be selected.
A similar observation can be made with other widgets such as RADIOGROUP and CHECKBOX that also have a different user experience in a CONSTRUCT.
To learn about why this is and how you can restrict entry to single values, read
https://4js.com/ask-reuben/ig-124/