PatchMerging is not correct for 3D.

[pooya-mohammadi]

MONAI/monai/networks/nets/swin_unetr.py

Line 781 in 9eb0a8c

x0 = x[:, 0::2, 0::2, 0::2, :]

t = [
    (0, 0, 0),
    (1, 0, 0),
    (0, 1, 0),
    (0, 0, 1),
    (1, 0, 1),
    (0, 1, 0),
    (0, 0, 1),
    (1, 1, 1),
    ]
print(set(t))
# {(1, 0, 1), (0, 1, 0), (0, 0, 0), (1, 0, 0), (0, 0, 1), (1, 1, 1)}

As you can see two of these are the same. To be exact, (x3, x6) and (x2, x5) are the same.

[ericspod]

This issue has been addressed by #8285 but can be re-opened if not.