On Qt 6.7.1 I'm still experiencing the bug described in QTBUG-120764, which apparently was resolved in 6.7.1: Opening a PDF in the Multipage Viewer Example, zooming in, searching and then jumping between the search results eventually breaks the search model: Both the search highlighting as well as the links to the search result break, meaning the highlighting is somewhere else than where the result actually is and clicking on a search result jumps to some other place instead of to where the result is located.

In the screenshot you can see the highlighting floating around somewhere in the PDF where it doesn't belong. In the video you can see that clicking on the search results doesn't always show the search results but instead just jumps to some other place.