Display issues with fractional scaling on Windows system.

This is an important client in China and they are currently experiencing a fractional scaling issue. The client's environment is Win11 with Qt 5.15, and the attached demo program reproduces the problem.
Upon verification, the same issue exists on Win10 with Qt 5.15.16.

1. Set the system scaling to 150%, run the demo and keep the process running. At this point, scrolling the scrollbar displays correctly.
2. Adjust the scaling to 100% or 200%, and scrolling the scrollbar displays correctly.
3. Adjust the scaling to 150% again, and scrolling the scrollbar causes item display issues.

Additionally, there is another issue:
The demo program utilizes the scaling policy Qt::HighDpiScaleFactorRoundingPolicy::PassThrough.
Initially, at 150% scaling, the program size is the same as when scaling is adjusted to 100%. However, when scaling is switched back to 150% at this point, the program becomes larger.
Alternatively, in the case of two 150% scalings (initial and after adjustment), the program size is inconsistent.