Xbee parameters goes to default values

I am using Xbee S8 (868) in API1 mode. The Xbee is connected to host controller over UART.
I use AT mode for setting Network ID of the device by changing the mode.
The problem is some times the values of Xbee parameters changes to default without me sending any RE command. Sometimes only one value changes. The values i am concerned about are Network ID and EE (encryption enable). It gets changed and my complete network gets affected.
Any inputs?

Are you using the Write parameter when setting the values?

Are you seeing any API status frames indicating a watch dog reset or anything?

I am setting these values using xctu, atleast the EE parameter. But the network-id is set by the host processor.
I am not seeing any frames indicating watchdog reset.
Does a watchdog reset sets these values to default?

As long as the settings are written to flash with the WR command, a watch dog reset would not change them.

Yes. I am using WR command. But my concern is how come the EE parameter is changed? I set this using xctu.

Do you see this occur when the module is NOT connected to your processor? That is, can you reproduce this outside of your hardware?

No. I have not observed this behavior outside of my hardware. Strangely this occur sometimes. But i have faced this quiet a few times.

Than it has to be something in your application that issuing the change of the command or an ATRE or something of that nature.

well. The application is not sing ATRE command. I will check it anyway. What else could be the reason?

If you have written the values to memory using the WR command, the only way to change them is by entering command mode and changing the value again, issue an ATRE via the local UART or either from an over the air command. That is it.

Can this happen because of power fluctuations?

If you mean by providing the radio less than then VCC Min? if so, than anything can occur when you operate out of the VCC Specification.