Samsung TV when off stops Q Mini box operating

[Virtual+Wizard]

I have a Samsung QE85QN90BA as my main TV connected to a Sky Q 2TB box. When I turn off the TV (Q 2TB still on) and turn on my Mini Q box upstairs it stops it from working saying there is an error. I can only seem to watch my Q Mini box when my main TV downstairs is switched on? When I turn the TV downstairs back on the Q Mini box connects instantly. It's a new TV so not sure if I need to change any settings. I had Panasonic TV previously and never had any issues. TIA