In Penpot, when you resize an object or group of objects, it changes its height and width, but it won't change the size of its properties, the type size, the stroke, the corner radiuses, and the shadows will stay the same size. This is a feature, not a bug.
In UI design, we usually keep values like border widths and type sizes consistent across our project. We don't want these properties to change just because we've made their container bigger. But there are cases where you do want to scale everything proportionally. Perhaps you have a logo design where the thickness of the stroke should remain proportional to the shape, or you're scaling a graphic to use in a different format and resolution.
You can scale objects proportionally in Penpot by activating the scaling tool from the preferences menu, or pressing the K keyboard shortcut. When you've enabled the scaling tool, the cursor changes from a single two-headed arrow to a double two-headed arrow. Any object you resize will be scaled proportionately when the scaling tool is enabled.
To return to default resizing, deactivate the scaling tool from the preferences menu, or press the K keyword shortcut again.