In order for Shaw to work you need:
-exactly the same lnbf as the one you use at home as your receiver is set up for that. If you have the new triple head at home and the older dual in Texas- it will not work. Shaw used to allow you to reprogram your receiver but that is proabably not so anymore if you are in the USA.
-the other possibility is that the dish is not pointed correctly.
You will need to provide much more information for a correct diagnosis.
-do you receive Shaw at home?
-did you upgrade to the triple head at home?
-is the present dish left in the USA or in the RV unused while at home?
-is it using the older dual head?
-did you bring the receiver which was working in Canada with you and is it the receiver presently not working?
According to others, Shaw does work in the south- but you will not receive the new G satellite with all its programming as its footprint does not cover the States.
You will receive the older 2 satellites as in the past.
M guess is that either the dish is not pointed correctly or you have a mismatched lnbf.
Hope this gives you a direction for diagnosis.
Good luck.