Hello, this issue hasn’t been fixed in 1.5.0, but has been fixed in 1.5.1:
v1.5.0:
    def train(self, mode=True):
        super(DistributedDataParallel, self).train(mode)
        for module in self._module_copies[1:]:
            module.train(mode)

is not returning self
v1.5.1
    def train(self, mode=True):
        self.training = mode
        for module in self.children():
            module.train(mode)
        return self

is returning self.