in only with and auto don't displayed

With the code below :

xml:
    <control type="group">

        <control type="panel" id="50">

            ....

            

            <itemlayout width="1088" height="64">

                <control type="label">

                    <left>90</left>

                    <width>auto</width>

                    <label>$INFO[ListItem.Label]</label>

                    ....

                </control>

            </itemlayout>

            

            <focusedlayout width="1088" height="64">

                <control type="label">

                    <left>90</left>

                    <width>auto</width>

                    <label>$INFO[ListItem.Label]</label>

                    ....

                </control>

            </focusedlayout>

    </control>

for all item unfocus

xml:
<label>$INFO[ListItem.Label]</label>

is displayed

With Item Focused

xml:
 <label>$INFO[ListItem.Label]</label>

is not displayed with the same property

Solution :

in <focusedlayout></focusedlayout> :
            
replace

xml:
<left>90</left>

with

xml:
<posx>90</posx>

or 

replace

xml:
<width>auto</width>

with

xml:
<width>500</width>

For me it is strange to not have the same behaviour with "<itemlayout></itemlayout>" and "<focusedlayout></focusedlayout>". 

So I hope you understand that I mean...
The solution is very simple but I'm a bit curious. Is this a known problem or is it normal ?

Anyway thanks for any answers