Channel switching - the screen goes black for a second or two before switching over

[AntS]

Hey there, @Gezza! :smileyhappy:

What's the model code of your TV? And are you switching between channels on the TV itself or on a set-top box? 

[Gezza]

Hi AntS,
Model is Ue43ku6400, When using sky remote or Samsung remote, on some channels the screen goes black before switching. However, On certain channels the switch is smooth with no delay