Debugging is not starting

Hello,
I would like to debug an Arduino MKRZERO with an Atmel-ice debug-adapter.
The Atmel-ice works fine with Microchip studio. I can read the chip-id of the Arduino MKRZERO. So the connection to the SWD-Interface is ok.
When I select the right program and start debugging in PlatformIO, the program is compiled and that’s it. No debugsession ist starting.

Best regards
Volker

Here the entrys from the ini-file:
[env:mkrzero]
platform = atmelsam
board = mkrzero
framework = arduino
monitor_speed = 115200
upload_port = COM10
debug_tool = atmel-ice
lib_deps =
stevemarple/AsyncDelay@^1.1.2
maizy/JC_Button_ESP@^2.0.2
adafruit/Adafruit ST7735 and ST7789 Library@^1.10.3