BlueNRG Readout Protection

[Roadrunner1805]

Hello,

I'm using BlueNRG-LP device and program my FW with RF-Flasher 4.3.0 in SWD mode. I set the "Readout Protection". Afterwards I cannot access the device anymore. From the manual RM0479 "Readout Protection" can be disabled with a mass erase. So I tried to get acces via UART mode. But unfortunately it's also not possible to get access via UART mode. I set "Auto baudrate" and tried "Mass Erase" without any success.
Do I something wrong? Or is this protection irreversible?

BR Sebastian