It seems that DynamicQuantizedLinear replaces the weight attribute with a method:
lin = torch.nn.quantized.dynamic.Linear(1, 1)
print(lin.weight())

So you might need to call self.field_cov.weight().t() + self.field_cov.weight().
Note that, while this might work functionality-wise, I’m not familiar enough with your use case or the dynamic quantization to claim it’s the right approach to use when quantization is applied.