Loose wifi after mac awakes from sleep

2 day old imac 21" 4k, 16mb, fusion drive etc etc

After I upgraded to High Sierra everytime the iMac wakes from sleep mode I have no internet access although it keeps searching for a network to join but does not seem to find one and remains disconnected from the internet, I can get it working by turning off wifi then turn it back on and works as it should.

Anyone else having this issue after upgrading to Hi Sierra?