If you set the screen's background color used for a call screen, the objects placed on the screen are not displayed on the display unit.
A maximum of 10 nesting levels (11 layers) can be set for Call Screens.
For example, 2 nesting levels (3 layers)
While creating the project, if the computer memory capacity gets low, and the screen is set up with multiple levels of call screens, the nested screens may not appear on the editor. However, once transferred to the display unit, they will display properly.