The observed differences might be caused by different implementations or different order of the operations.
Since the differences are at approx. 1e-6 it’s likely the reason in my opinion.
Have a look at the following code:
a = torch.randn(10, 10, 10)
b = a.sum()
c = a.sum(2).sum(1).sum(0)
print(b)
print(c)