Incompatible return value type when using typevar with bound and self returning method

Bug Report

Using a typevar bound to a class that has a self returning method leads to an error when using in a function that operates on the typevar and returns the typevar.
Using constraint does not present the issue but looses the generic on the class.

To Reproduce

# pyright: strict
from typing import Any, Generic, TypeVar
from typing_extensions import Self, reveal_type

T = TypeVar("T")


class X(Generic[T]):
    def m(self, v: int) -> Self:
        return self

class Y:
    def m(self, v: int) -> Self:
        return self

# using bound: tb_self errors with Incompatible return value type
TB = TypeVar("TB", bound=X[Any] | Y)

def tb_self(value: TB) -> TB:
    return value.m(42)

def tb(value: TB) -> TB:
    return value

reveal_type(tb_self(X[int]()))
reveal_type(tb(X[int]()))

# using constraint: return type is X[Any] in both cases
TC = TypeVar("TC", X[Any], Y)

def tc_self(value: TC) -> TC:
    return value.m(42)

def tc(value: TC) -> TC:
    return value

reveal_type(tc_self(X[int]()))
reveal_type(tc(X[int]()))

https://gist.github.com/mypy-play/3f911f7de9e2282fb6463a7146ffae47

The output is:

file.py:20:12: error: Incompatible return value type (got "X[Any] | Y", expected "TB")  [return-value]
file.py:25:13: note: Revealed type is "try_.X[builtins.int]"
file.py:26:13: note: Revealed type is "try_.X[builtins.int]"
file.py:37:13: note: Revealed type is "try_.X[Any]"
file.py:38:13: note: Revealed type is "try_.X[Any]"
Found 1 error in 1 file (checked 1 source file)

For reference pyright on the same input reports no error

Expected Behavior

The is no error.

Actual Behavior

Mypy reports an error when the using a self returning method

Your Environment

• Mypy version used: 1.9.0, 1.7.1
• Mypy command-line flags: none
• Mypy configuration options from mypy.ini (and other config files): -
• Python version used: 3.10, 3.12

Beginne damit, das bereitgestellte Beispiel mit mypy 1.9.0 und den angegebenen Python-Versionen zu reproduzieren, und vergleiche dann die Fälle mit gebundenem und eingeschränktem TypeVar sowie deren aufgelöste Typen. Als erledigt gilt die Aufgabe, wenn die Methode, die sich selbst zurückgibt, keine Diagnose wegen einer inkompatiblen Rückgabe erzeugt und dabei den generischen Typ beibehält, der in der erwarteten reveal-Ausgabe angezeigt wird.