Cannot lock onto Nimiq 91on Dual lnb

If all you did was move the dish and nothing changed in receiver setup. Just moved and mounted the dish.
One thing could be you have the lnb cabling reversed or one of the lnb's is aimed at the opposite satellite.
Remember. Looking at the sky from behind the dish. The right lnb is "looking" on the left of the sky and vice versa.
Another thing comes to mind is the skew angle may be off. One lnb could be aimed dead on but the other would be looking low or high in the sky. Because the sat are in an arc.
 
If all you did was move the dish and nothing changed in receiver setup. Just moved and mounted the dish.
One thing could be you have the lnb cabling reversed or one of the lnb's is aimed at the opposite satellite.
Remember. Looking at the sky from behind the dish. The right lnb is "looking" on the left of the sky and vice versa.
Another thing comes to mind is the skew angle may be off. One lnb could be aimed dead on but the other would be looking low or high in the sky. Because the sat are in an arc.
Very little skew difference in Manitoba. Winnipeg is at longitude 97 West, with the two Nimiq satelllites not far away, at 91 and 82 West. More likely the LNB cabling is reversed as you have suggested.