Problem with listeners and modifiers/custom lists

There seems to be a bug when setting listeners to values of modifiers.

This works as expected
self.song().tracks[0].devices[0].add_chains_listener

But when using modifiers (that definately store the correct value) this doesn’t work and the listener never fires:
self.song().tracks[self.get_modifier_value("m1")].devices[self.get_modifier_value("m2")].add_chains_listener

Can someone confirm?