Setting settings.debug.visualize_cells=True/False causes different table output

### Bug
I have pre-ocr pdf with following layout.
```
Logo Page Header
Key-value Items Figure

Section Header1
Table1

Section Header2
Table2
```

1. settings.debug.visualize_cells=False, only Table2 is detected.
2. settings.debug.visualize_cells=True, Table1 and Table2 are detected and merged to one table.
Both outcomes are wrong .

Second case can be solved by modifying file docling/models/page_preprocessing_model.py
before:
```
if settings.debug.visualize_cells:
draw_text_boxes(page.get_image(scale=1.0), page.cells)
```

after:
```
if settings.debug.visualize_cells:
draw_text_boxes(page.get_image(scale=1.0).copy(), page.cells)
```

...

### Steps to reproduce
Play with settings.debug.visualize_cells
...

### Docling version
Docling version: 2.28.4
Docling Core version: 2.25.0
Docling IBM Models version: 3.4.1
Docling Parse version: 4.0.0
Python: cpython-310 (3.10.15)
Platform: Linux-5.15.167.4-microsoft-standard-WSL2-x86_64-with-glibc2.35
...

### Python version
Python 3.10.15
...