### ImageMagick version

7.1.1-21

### Operating system

Linux

### Operating system, version and so on

Debian bullseye

### Description

I was trying to make a `caption:` best fill a box horizontal and vertical. When the `caption:` starts with a capital letter or `"` the auto-fit works. However, when it starts with a lowercase letter it fails to utilize all vertical space.  

### Steps to Reproduce

This fit best in both axis
```
convert -background grey -fill black -gravity Center -size 330x330 caption:"This is a very long caption that should fill the grey box as most as possible and not only stick the the horizontal"  out.jpg
```
This fails to utilize all vertical space:
```
convert -background grey -fill black -gravity Center -size 330x330 caption:"this is a very long caption that should fill the grey box as most as possible and not only stick the the horizontal"  out.jpg
```

### Images

![lower](https://github.com/ImageMagick/ImageMagick/assets/20991420/0b7fa6ca-b9ad-4a35-ac8d-7a0c85d93655)
![Capital](https://github.com/ImageMagick/ImageMagick/assets/20991420/7974b366-6da0-4847-83c5-141578efa0d0)

Caption: weird behavior depending on first letter capitalization  
This is a GitHub Issue
repo:ImageMagick
owner:ImageMagick
Title : Caption: weird behavior depending on first letter capitalization  
Issue date:

--- start body ---
### ImageMagick version

7.1.1-21

### Operating system

Linux

### Operating system, version and so on

Debian bullseye

### Description

I was trying to make a `caption:` best fill a box horizontal and vertical. When the `caption:` starts with a capital letter or `"` the auto-fit works. However, when it starts with a lowercase letter it fails to utilize all vertical space.  

### Steps to Reproduce

This fit best in both axis
```
convert -background grey -fill black -gravity Center -size 330x330 caption:"This is a very long caption that should fill the grey box as most as possible and not only stick the the horizontal"  out.jpg
```
This fails to utilize all vertical space:
```
convert -background grey -fill black -gravity Center -size 330x330 caption:"this is a very long caption that should fill the grey box as most as possible and not only stick the the horizontal"  out.jpg
```

### Images

![lower](https://github.com/ImageMagick/ImageMagick/assets/20991420/0b7fa6ca-b9ad-4a35-ac8d-7a0c85d93655)
![Capital](https://github.com/ImageMagick/ImageMagick/assets/20991420/7974b366-6da0-4847-83c5-141578efa0d0)

--- end body ---
