Bluno nano without connection between Arduino-USB-BLE modules?

Hi, I have three DFRobots Bluno Nano, all of thoose with BLE. THe problem is that one of them, in the start of the project, didn't wanted to accept my sketch, so I used another arduino to upload it as ISP. I though that it could be a bad update, but after one hour, another Bluno had the same issue (By the way, The error was the "Not responding/not in sync"), and after another hour, the third Bluno had the exactly the same problem.

It's super weird, because:

1. 1) I can't upload the sketch from USB
   2) But I can upload from ISP with another arduino
   3) The sketch can't call any AT Command by itself (or, in fact, it never could interact with the AT Command
   4) But I can call all the AT Comands by USB, using Serial
   5) But, finally, the arduino can't send me data by serial. (If I make a simple sketch where in the loop it sends me "hi", I can't get that in the serial monitor, but the TX blinks as suppose to be

Also, when I try to upload the sketch from the USB, the RX and the TX leds binks toghether twice (or 3 times), but then nothing. If I use an arduino nano or Uno to see what should happen, the TX and RX blinks togheter, then the RX blinks randomly and then the TX blinks randomly, or something like that.


I Tried to upload the bootloader again (using an arduino uno), but, although it's says that the upload was done, the issue persists.
What should be?