Heltec T114 (nRF52840) lost configuration after getting wet... why?

[MartinEmrich]

Snowy, cold, clammy, wet, rainy bike ride today. Somehow my T114 got wet, LEDs started to flash and glow randomly, display dead.
Got home, cleaned the corrosion (certainly got wet before) with contact cleaner and IPA, hardware works again. My fault!

But afterwards, it started with the new-device-setup assistant. Whole config including keypair is gone (PSA: back up keys and config ;)

The firmware and the node list survived, the configuration did not.

At least on ESP32, everything is saved in the same SPI flash, either builtin or separate flash chip via SPI.
So this should be an all-or-nothing thing.

Now how is nRF architecture different in terms of NVS, that only the node configuration got lost? Just curious...