Business trip to Canada on a TN-1

This trip is for the same employer as my TN visa.
Would this be an issue at customs in both the U.S. and Canada?

I'm only there for a couple days, so claiming to be visiting friends and family would be suspicious and risky.

Can't see why it would be.

You're Canadian, and therefore allowed to come and go as you please, and even work if you want to, regardless of your status in the US.