ra series chip flash problem

Hello.

       I am working with RA6T1 chip.

       Today when I debug it with e2studio, the console report this:

       I tried several times, it always be like this. And I tried another ra6t1, it works good.

       So I think maybe the code flash of this chip is damaged.

       I use this problem chip less than 6 month, and in my application software, it will erase and program the code flash, but this operation is not so much times,

I think the total erase and program times of this chip is less than one thousand. And I test my software again today, it erase and program flash very less.

        So I am confused about this. I checked the manual, it doesn't tell me the exact erase times, but it should be more than 100,000 cycles according my experience.