TabView content position issue

The project included have two Panels: Panel2 and Panel3. It have the same coordinates (0,0) and aligned as LEFT MID. As you can see Panel2 aligned correctly, but Panel3 have a x=20px (approx) error. What is wrong here?

SLS v1.3.3
Win11-64 (5.2 KB)

This is not an SLS bug. In the TabView the default padding (used internally by LVGL default dark/light theme) is nonzero value so there’s a gap between the TabView side and the contained widget.
If you want to align your Panel3 widget totally to the left without having this gap, go to TabPage’s ‘STYLE SETTINGS’ / ‘STYLE (MAIN)’ section in the Inspector panel and tick the box inside ‘Paddings’ setting, and leave the 0 values as theye are.
(You may consider selecting ‘Simplified’ theme as a base when you create your project if you want to eliminate default paddings.)