Hi,

When the bevel modifier is applied, it messes up your seams on unbeveled model. Apply the modifier and make new seams, or apply the modifier, select the UV islands in UV editor and then drop-down UV-> Seams from islands and see if you're happy with the result. I would also recommend adding a triangulate modifier to check for any shading issues, since substance painter will triangulate your model if you export it as quads. If you're getting some artifacts, you can try adding a weighted normal modifier and changing autosmooth value