mypy type checking seems to break in strict mode -- a mypy bug?

Following up on https://github.com/patrick-kidger/torchtyping/issues/41 I'm trying the same things here. However I'm not really having a big success so far with mypy. Am I doing anything wrong?

import torch
from jaxtyping import Float

dim1 = "dim1"


# Expected to work but fails with:
# error: Returning Any from function declared to return "Tensor"
def simple_test_a(x: Float[torch.Tensor, "dim1"]) -> torch.Tensor:
    return x


# Expected to work but fails with:
# error: Returning Any from function declared to return "float"
def simple_test_b(x: Float[torch.Tensor, "dim1"]) -> float:
    return x.item()


# Expected to error, but passes type checking
def simple_test_c(x: Float[torch.Tensor, "dim1"]) -> None:
    x.asdfasdfasdf()

VSCode (pyright) seems to do a little better, but apparently doesn't like the import:

Start by reproducing the three snippets from the issue with mypy in strict mode, then compare the reported behavior with pyright. Determine whether the failures come from jaxtyping, PyTorch typing, or the type checkers; done means identifying the cause and documenting or fixing the relevant behavior.