The custom forw method works for me using this minimal code snippet:
class Net(nn.Module):
    def __init__(self):
        super().__init__()
        self.lin = nn.Linear(1, 1)
    
    def forw(self, x):
        x = self.lin(x)
        return x

model = Net()
x = torch.randn(1, 1)
out = model.forw(x)

(I had to remove parts of your model, which were undefined), but I would generally not recommend to use this approach and to implement the needed forward method to be able to call the model directly and to make sure that e.g. hooks are working properly.
PS: you can post code snippets by wrapping them into three backticks ```, which makes debugging easier.