Hello @Kenwang
I'm able to reproduce this behavior using STM32CubeIDE 1.17.0, STM32Cube_FW_WBA_V1.5.0 and STM32CubeMX 6.13.0 and I've escalated for correction on the coming releases (under internal ticket number 197703).
As a temporary workaround, could you please go to \STM32Cube_FW_WBA_V1.5.0\Projects\NUCLEO-WBA55CG\Applications\BLE\BLE_p2pServer\STM32CubeIDE and open the .cproject file. That should work fine. or go to File\Open Projects from file System... and select \STM32Cube_FW_WBA_V1.5.0\Projects\NUCLEO-WBA55CG\Applications\BLE\BLE_p2pServer\STM32CubeIDE on the Import source Directory and click on finish.
Best Regards.
STTwo-32