Hi,
Are you using Float or Double tensors? Keep in mind that below 1e-7, a single float will not be precise and such values should not be considered correct.
Some operations (especially on GPU) are non-deterministic and so can give different results where the difference is of the order of floating point precision: 1e-7 1e-8.
If you use cudnn, you can set cudnn.deterministic = True to get deterministic results.