@jarens It's best to give each sort formula a different column name, to help distinguish them. I had this problem a while back and ended up doing this in my scripted search:

columns: [
    { name: 'formulatext_sort', formula: '...' },
    { name: 'formulatext_name', formula: '...' },
    { name: 'formulatext_memo', formula: '...' },
    { name: 'formulatext_item', formula: '...' },
    { name: 'formulatext_unit', formula: '...' },
    { name: 'formuladate_service', formula: '...' },
    { name: 'formulatext_quantity', formula: '...' }
]