My C5 x7 with Ng4 has suddenly decided to become Peugeot

I've had the car for over 8 years with its original ng4 system updated to latest firmware 4-5 years ago.
Everything was fine unit today when its started showing Peugeot logo on starting.
I have Diagbox and I have tried to find some option to put it back to Citroen but I wasn't able to find anything.
Is there some option in Diagbox?
If so, can someone expalin to me how to fix this.
Thanks
