When rearranging the form, the client experienced a blocker to arrange the fields in a single row. Even if unchecked the column break checkbox for each field, the fields were in multiple rows.
The reason for this was the field group settings.
For each field group, there is an option called ‘Single Group’. If this option is checked, all the fields in the group will be in a single column aligned in multiple rows.
Uncheck the option and the fields will be in single row and multiple columns.