### Godot version

4.0 beta 10

### System information

Windows 11 Vulkan

### Issue description

Looked through the issues list, but couldn't find something like this, sorry in advance if this has already been reported.

There is a few cases (in the pictures below) where list of Actions in Input Map may not always show a scrollbar even if the actions list overflows (I imagine this could also happen for the widget that Input Map uses).

![image](https://user-images.githubusercontent.com/39958198/210003566-cf60dbaf-921f-485b-b0a9-51ffc28d0244.png)

![New Bitmap image](https://user-images.githubusercontent.com/39958198/210004079-8eb2e6a1-0cf5-4a7c-8905-a4e3cfd0ec5d.png)

![image](https://user-images.githubusercontent.com/39958198/210004165-a6b6790b-248a-4f68-b4d0-b44b25afdf4f.png)

![image](https://user-images.githubusercontent.com/39958198/210004537-aca52194-a464-48b9-b818-24782706de45.png)


### Steps to reproduce

The pictures are clearer than anything I could write here: "a picture is worth 1000 words"

### Minimal reproduction project

N/A
}
			bg->draw(ci, Rect2(Point2(), get_size()));
			int tbh = _get_title_button_height();
			draw_ofs.y += tbh;
			draw_size.y -= tbh;
			cache.rtl = is_layout_rtl();
			if (root && get_size().x > 0 && get_size().y > 0) {
				draw_item(Point2(), draw_ofs, draw_size, root);
			}
			if (show_column_titles) {
				
				int ofs2 = theme_cache.panel_style->get_margin(SIDE_LEFT);
				for (int i = 0; i < columns.size(); i++) {
					Ref<StyleBox> sb = (cache.click_type == Cache::CLICK_TITLE && cache.click_index == i) ? theme_cache.title_button_pressed : ((cache.hover_type == Cache::CLICK_TITLE && cache.hover_index == i) ? theme_cache.title_button_hover : theme_cache.title_button);
					Ref<Font> f = theme_cache.tb_font;
					Rect2 tbrect = Rect2(ofs2 - theme_cache.offset.x, bg->get_margin(SIDE_TOP), get_column_width(i), tbh);
					if (cache.rtl) {
						tbrect.position.x = get_size().width - tbrect.size.x - tbrect.position.x;
					}
					sb->draw(ci, tbrect);
					ofs2 += tbrect.size.width;
					
					int clip_w = tbrect.size.width - sb->get_minimum_size().width;
					columns.write[i].text_buf->set_width(clip_w);
					Vector2 text_pos = tbrect.position + Point2i(sb->get_offset().x + (tbrect.size.width - columns[i].text_buf->get_size().x) / 2, (tbrect.size.height - columns[i].text_buf->get_size().y) / 2);
					if (theme_cache.font_outline_size > 0 && theme_cache.font_outline_color.a > 0) {
						columns[i].text_buf->draw_outline(ci, text_pos, theme_cache.font_outline_size, theme_cache.font_outline_color);
					}
					columns[i].text_buf->draw(ci, text_pos, theme_cache.title_button_color);
				}