that’s kinda related to float32 precision, as 1e-8 < 2**-23 = 1.19e-7
and
torch.erfinv(torch.tensor([1-2**-23])) -> 3.7439
issue is this:

np.float32(1)-np.float32(1e-8)
1.0
np.frexp(np.float32(1)-np.float32(1e-8))
(0.5, 1)