Seams & gaps in modular meshes

I have some jigsaw puzzle piece meshes I've made in Blender from a SVG file, in both Blender and the original svg file all the pieces are aligned perfect with no gaps/seams. Once exporting to fbx and trying to use them in Unity the are these tiny gaps/seams in between the mesh pieces that appear/disappear as you are panning and zooming the camera around.I double checked the Blender file, all the pieces are perfectly aligned with vertices on connecting piece aligned exactly, when imported into Unity they align but all these gaps/seams keep appearing. I've tried adjusting the AA settings and turning AA off as well, tried adjusting camera clipping planes, I'm not sure that is causing all these gaps/seams, any advice would be appreciated.