You've been hit with this issue:

https://github.com/espressif/esp-idf/is ... 1283878072

Stick the device in the bin, it's bricked.

I'm seeing this problem, interestingly on an E device which seems to be the same as the other posters here.

I have.4 devices under test, they wake up every 30 minutes from deep sleep, connect to wifi, publish their data, go back to sleep.

3 are still working.
1 died within 12 hours.

The dead one ...