Implementing generic trait for dyn T is not allowed when a supertrait with different type parameter is present

I tried this code:

mod supertrait {
    trait V<T> {}
    trait A : V<u32> {}
    struct T {}
    impl A for T {}
    impl V<u32> for T {}
    impl V<i32> for dyn A {} // `(dyn A + 'static)` automatically implements trait `V`
}

mod nosupertrait {
    trait V<T> {}
    trait A {}
    struct T {}
    impl A for T {}
    impl V<u32> for T {}
    impl V<i32> for dyn A {} // ok
}

I expected to see this happen: No error in either case.

Instead, this happened: Using a supertrait causes the compiler to complain about auto implemented trait as if type parameters are not being taken into account.

Meta

rustc --version --verbose:

rustc 1.88.0 (6b00bc388 2025-06-23)
binary: rustc
commit-hash: 6b00bc3880198600130e1cf62b8f8a93494488cc
commit-date: 2025-06-23
host: x86_64-pc-windows-msvc
release: 1.88.0
LLVM version: 20.1.5

<backtrace>

Start by compiling the minimized Rust example from the issue with rustc 1.88.0 and confirm that the supertrait case fails while the nosupertrait case succeeds. Trace the compiler's handling of the generic trait implementation for dyn A and its supertrait obligations; done means both examples compile without incorrectly treating V as V.