HARMONY weird phenomenon in SPI EEPROM Developer's Help Example

We have built our own board based on PIC32MX795F512L and this device is in production. We've upgraded the device installing an SPI EEPROM chip. I've managed to get things going on the SPI EEPROM communications. As the next step, I've integrated this code to my project. Testing my new device I've realised that when the microcontroller is saving any data bytes in the following  addresses: 
3F,7F,BF,FF and 13F,17F,1BF,1FF also 23F,27F,2BF,2FF (and I assume this will go on up until the end of the EEPROM space),
there is no saving taking place. The contents are NOT changing at all. I've tested three (3) different EEPROM chips (M951258) on two (2) different boards. Any ideas why this is happening?
Thank you Guys
 
PIC32MX795F512L, MPLABX v.5.05, XC32 v.2.2, Harmony 2.06, EEPROM M951258