Text selection in desktop behaves abnormally

[jxqu3]

Bug Description

Selecting text in a standard TextEdit widget behaves abnormally when there are enough lines to fill the height of the textbox, thus allowing scrolling, a slight downward movement moves the cursor all the way down, and it often flickers from top to bottom, making it almost impossible to select text precisely where there are multiple lines. It's hard to explain what I'm referring to so I made a video

2026-01-20.07-36-52.mp4

Reproducible Code (if applicable)

export component AppWindow inherits Window {
    min-width: 500px;
    min-height: 500px;
    title: "File Explorer Test";
    ScrollView {
        VerticalBox {
            padding: 20px;
            spacing: 20px;
            alignment: start;
            TextEdit {
                
                placeholder-text: "text";
                height: 50px;
            }
        }
    }
}

Environment Details

• Slint Version: 1.14.1
• Platform/OS: Windows 10
• Programming Language: None/Slint only
• Backend/Renderer: windows default with cupertino

Product Impact

It makes desktop applications developed with Slint feel buggy and unfinished, and is mostly the only reason why I'm not using slint as of now.

[tronical]

This is reproducible with the fluent style. But I don't think that it's a bug in the fluent style.