In a wireless project, I'm using en Nucleo STM32WLJC1 in dual core configuration. I take DualCore Ping Pong ST code example, that I rework to make my own application. I didn't touch anything of the CMO+ project, I only work on the applicative layer in CM4.

I've some problems about flashing the CM0+ Core.
The first time I flashed the board it works and now I've most of the times the folowing error when I try to flash the CM0+. It sometimes work one time for no reason.

Pop-up Problem Occurred Windows :

 Error in final launch sequence:
 Failed to start GDB server Failed to start GDB server Error in
 initializing ST-LINK device. Reason: (255) Unknown. Please check power
 and cabling to target.

Console informations

STMicroelectronics ST-LINK GDB server. Version 6.0.0 Copyright (c)
2021, STMicroelectronics. All rights reserved.
Starting server with the following options:
Persistent Mode            : Disabled
Logging Level              : 1
Listen Port Number         : 61234
Status Refresh Delay       : 15s
Verbose Mode               : Disabled
SWD Debug                  : Enabled
 
Target unknown error 32

Error in initializing ST-LINK device. Reason: Unknown. Please check
power and cabling to target.

It looks like the STlink can't reach the core...

• Someone may know what is happening ?
  
• Is there a flashing configuration that has to be done? (to chose which core we want to flash)