Evidently the label next to the listbox is kind of its own control (partially). You need to set properties for the label indepently of the main listbox for some properties. Try this:
% Value changed function: Switch
function SwitchValueChanged(app, event)
value = app.Switch.Value;
% [app.ListBox.Enable, app.ListBox2.Enable] = deal(value);
if contains(value, 'On', 'IgnoreCase',true)
% Enable the items inside the listbox.
app.ListBox.Enable = 'On';
app.ListBox2.Enable = 'On';
% Enable the text labels beside the listbox.
app.ListBoxLabel.Enable = 'On';
app.ListBox2Label.Enable = 'On';
% Enabled. Make text green (optional)
app.ListBoxLabel.FontColor = [0, 1, 0]
app.ListBox2Label.FontColor = [0, 1, 0]
else
% Enable the items inside the listbox.
app.ListBox.Enable = 'off';
app.ListBox2.Enable = 'off';
% Enable the text labels beside the listbox.
app.ListBoxLabel.Enable = 'On';
app.ListBox2Label.Enable = 'On';
% Disabled. Make text red (optional)
app.ListBoxLabel.FontColor = [1, 0, 0]
app.ListBox2Label.FontColor = [1, 0, 0]
end
end
