Satellite 119 with DISH seems to cut in and out on motorhome

I'm using Dish in my house and on the HM also. Here lately at home between 5 and 7 pm we've been experiencing the complete signal loss intermittently. The strange thing is, when we press the GUIDE button during one of these episodes, the picture comes back in the window and stays there. Eventually, the Guide times out and switches back to full screen where we get the signal loss message again. We're using a Vip211z receiver. I think the problems has to do with the sun overpowering the satellite signal but I'm not sure.