Is it only on one side? It is probably the part C-01409 rail which sets the curvature of the canopy rail. This part comes together with the L and R part that have to be cut apart. See if they are symmetrical. I bet they are not. The edges are folded down on a press and sometimes they are not pressed correctly. measure two things. the distance of the rivets from the edge. Also, if the relationship of the bottom edge relative to C-01407. The 1407 should come down and be right at the edge of the 1409. Make sense.
I doubt it has anything to do with the aft edge of the canopy since that is set by the the assembly of 1405L/R on 38-14 and that brace is used to make sure that the distance is correct at the aft of the canopy.
I had to get a new part and remove the original one. I only replaced one of them. The other seemed to be fine, which I know does not make sense. Van's knows that this is an issue. Not sure why they don't check each part before putting in a kit.
I had a post about this at the beginning of the summer (2018).
EAA Chapter 1093 member
RV-14 (serial number 140073)
N73XP (at least that # reserved now)