Cell value vertical alignment not working

[th3ygen]

Hello, I tried to align a merged cells value both vertically and horizontally. The value inside the cells did aligned but only horizontal.

Here's my code

const totalIndex = 3;
for (let x = 0; x < totalIndex; x++) {
    wb.Sheets.Data[`A${(x * 4) + 5}`] = { t: 's', v: `${x + 1}`,
        s: {
            fill: { style: 'solid', fgColor: { rgb: 'baff4c' } },
            border: {
                top: { style: 'thin', color: { rgb: '000' } },
                right: { style: 'thin', color: { rgb: '000' } },
                left: { style: 'thin', color: { rgb: '000' } },
            },
            alignment: {
                vertical: 'center', horizontal: 'center'
            }
        }
    };
    wb.Sheets.Data['!merges'].push({ s: { r: (x * 4) + 4, c: 0 }, e: { r: (x * 4) + 7, c: 0 }});

    wb.Sheets.Data[`A${(x * 4) + 6}`] = {
        s: {
            border: {
                left: { style: 'thin', color: { rgb: '000' } },
                right: { style: 'thin', color: { rgb: '000' } },
            }
        }
    };
    wb.Sheets.Data[`A${(x * 4) + 7}`] = {
        s: {
            border: {
                left: { style: 'thin', color: { rgb: '000' } },
                right: { style: 'thin', color: { rgb: '000' } },
            }
        }
    };
    wb.Sheets.Data[`A${(x * 4) + 8}`] = {
        s: {
            border: {
                left: { style: 'thin', color: { rgb: '000' } },
                right: { style: 'thin', color: { rgb: '000' } },
                bottom: { style: 'medium', color: { rgb: '000' } },
            }
        }
    };
}

Result