-- reproducibity finger print
b1.sum()=-0.3949629209972978
b2.sum()=5.1787780003950825
b1_t.sum()=tensor(-0.3950, dtype=torch.float64)
b2_t.sum()=tensor(5.1788, dtype=torch.float64)
b1.shape=(7, 12)
b1_t.shape=torch.Size([12, 7])

I wonder how you managed to generate random arrays with almost perfect 0 mean both times