When a screen number that does not exist is set, a screen change will not function.
When you set a switch with the [Group with Auto OFF] setting, the bit will automatically turn OFF when the screen changes.
To use the direct access method and memory link method together, from the [System Settings] window click [Display Unit], and in the [Display] tab select the [Reflect in Device/PLC] check box. If you do not select the [Reflect in Device/PLC] checkbox, screen change via memory link is disabled. Even if you write the screen number to memory link address "0015", the value changes to LS0008 right away by direct access communication.
For more details, please refer to the following.
2.4.3 Using Direct Access and Memory Link at the Same Time
To change screens from both the display unit and the device/PLC, from [System Settings] click [Display Unit], and in the [Display] tab select the [Reflect in Device/PLC] check box. If you do not use the [Reflect in Device/PLC] check box, design your system so that after a screen change you clear (0) the screen change number in the device/PLC's [System Area Start Address]+8. Without clearing the address content, screen changes may not run properly, or screen changes may occur unexpectedly.
From the [Project] menu's [System Settings], select [Display Unit]. In the [Display Settings] tab, if you select the [Reflect in Device/PLC] check box and set [Standby Mode] to [Screen Change], you cannot use the [Previous Screen] operation in a change screen switch to return to the screen defined in the [Change-To Screen in Standby Mode] field. Instead, you will return to the screen that was open prior to the previous screen. If this screen does not exist, the screen will not change.
If you are using a ladder program to clear (0) the screen change number in the device/PLC's [System Area Start Address]+8, do not use the [Reflect in Device/PLC] setting.
To run a forced screen change from the device/PLC, in the device/PLC's [System Area Start Address]+8, turn ON bit 15 (forced screen change bit), and in bits 0 to 14 specify the change screen number. In other words, add 8000(h) to the change screen number. While Bit 15 is ON, you use touch operations to change screens. However, you can also use the system variable #H_ChangeScreenNo to change screens.