Material UI Select does not work properly

Question

MenuItems are displayed horizontally

How it looks:

https://prnt.sc/iCj6O1en1H08

Code:

     <Grid item xs={2} sm={4} md={4}>
          <FormControl fullWidth>
            <InputLabel id="demo-simple-select-label">Age</InputLabel>
            <Select
              labelId="demo-simple-select-label"
              id="demo-simple-select"
              value={age}
              label="Age"
              onChange={handleChange}
            >
              <MenuItem value={1}>
                <Typography>1</Typography>
              </MenuItem>
              <MenuItem value={2}>
                <Typography>2</Typography>
              </MenuItem>
            </Select>
          </FormControl>
        </Grid>