Slitherine

I just finished the Securing the plain of Catania and have placed Canadian units into the towns mentioned for the historical bonus but no bonus was given.

Here is the last turn and you can clearly see that the Canadian flag is over the towns mentioned...

I went back and tried it again and experimented.

It seems that Canadian HW Infantry do not count as Canadian!
When I used the Canadian Infantry 43 unit instead, I got the achievement...