ADucM355 Flash lock

Hi , Analog Team,

The Eval-ADucM355QSPZ which we received  worked well ,  ... till yesterday.

We can not program/Erase the internal flash any more,

The J-link can attach the cpu core through swd,(See debug-log), but the flash seems "locked".

And we follow the user-guide-1308 to enter boot-mode, to erase the entire internal flash,

But it seems fail. Can you suggest any action we can do to solve it ?

Thanks for your help

Joseph