You need to state EXACTLY what you did.
To also explain:
If you're on 12625 and dump the NAND, your LDV will be 'n'
You've updated it to 13604, meaning LDV is now 'n+1' - it increments.
Therefore the old dump of 'n' will no longer be valid.
If you can't read/write to the NAND, you'll need to it via the 'bad flash' method.
I'm guessing you used +w and not -w to write it back, yes?