PdfSearchModel skips first match during first run

When using PdfSearchModel for text search, the first match is skipped if the search is initiated from the first page. To reproduce the issue:

1. Run the example project: https://code.qt.io/cgit/qt/qtwebengine.git/tree/examples/pdf/singlepage
2. Load the attached text-based PDF document.
3. In the search panel (bottom left), enter the word "help".
4. Click the down arrow (search forward) next to the input field.

Expected: The first match should be found on page 2.
Actual: The first match is shown on page 3.

If you press the up arrow (search backward), page 2 is found correctly.
It seems the issue only occurs when the search starts from the first page and moves forward.

Compiler: MinGW 13.1.0

Let me know if you need more information.