You probably have defective tires, this problem has been reported by a few folks here. My wife's 2014 RTL had the same problem, even after a laser alignment. The moment you let go of the handlebars they will consistently move about 1/4" to 1/2", to the right in our case. We bought the Spyder at the start of winter so it didn't get ridden much for a few months and by the time we convinced ourselves there was an actual problem it was time for the first service. The dealer temporarily swapped the front tires, the standard test for this, and the pull moved to the left. BRP would not warranty it claiming it was past the 90 day tire warranty, even though this is a known factory defect that does not always show up right away. Shame on them!
Shame on them!
I put some real tires on the front and the problem went away and the Spyder now rides like a dream! I can't believe how much the overall ryde has improved. I'm looking forward to when the tires wear out on my 2013 RS so I can put some real tires on it!
Here is a video I made comparing my silver RS with her cognac RTL over the same course - blow up the video to full screen (click YouTube) so you can see the handlebars better:
Good luck with your problem, I hope you can get it resolved.