Nissan Elgrand stuck in 4 wheel drive

Since replacing both front wheel bearings and brake sensors it won’t toggle back and forth between 2w drive & 4w drive as it used to the indication lights on the dash board has a little diagram with 4 wheels & the diff when in 2 wheel drive the 2 rear wheels were lit up green when you pressed the 4w drive button all 4 wheels lit up green now what happens is when you first turn on the ignition all 4 wheels light up green then all go off and the is an indication that it is in 4w drive all the time when you turn snow on that comes on and off with the switch and also power.