Secondary box not working

Looking for some help we have two cable boxes the main one in the living room and the secondary one in my room. We decided to move the main box down to the basement to our new tv room and it works but my box has no signal and I have to put the main box back in the living room for mine to work again. I've tried rebooting my box while the other one is hooked up in the basement and have tried swapping the two mine in the basement and the main box in my room but it's the same. The guy at the xfinity store said it shouldn't be an issuse to have the boxes two floors apart but I can't come up with any other explanation. So is there anyway to have the main box in the basement and my box still work? Both boxes are wired not wireless any help would be appreciated