I suppose you selected the wrong range.

I can reproduce the problem only with the last 2047 bytes, from 0x01FFF801 to 0x01FFFFFF.

If I modify even a single byte at 0x000000FF, then the "verify" detects it

Hi, the verify command isn't reliable! It doesn't check the last 2047 bytes of a buffer. Tested with revelprog is v1.8.2 and v1.8.3 Steps to reproduce Chip: MX25L25735F Read the chip Then select the bytes from 1FF:F801 to the end Fill the selected range (ALT-F) with some pattern Start "Verfiy&q...