Hello! When you have a parentless temp copy of a layer (not assigned to any glyph), it’s bezierPath doesn’t get updated with any changes to the GSPaths. Also, its completeBezierPath is None.
Try this with a layer with a path:
Glyphs.clearLog()
layer_copy = Layer.copy()
layer_copy.paths[0].nodes[0].y = -6 # bezierPath ignores this
print(layer_copy.paths[0])
print(layer_copy.bezierPath)
print(layer_copy.completeBezierPath) # This is None
It used to work a few months ago, so I wonder if it now requires manually calling an update of some sort?