Regression in Scala 3.5.0-RC1 related to match types in using parameters

[mrdziuban]

Compiler version

3.5.0-RC1, the issue is not present in 3.4.2

Minimized code

case class Foo[A]()
case class Bar[A]()

type TestMatch[F[_]] = [A] =>> F[Unit] match {
  case Foo[Unit] => Bar[A]
}

trait TestTC1[A]
object TestTC1 {
  given inst: TestTC1[Bar[Int]] = new TestTC1[Bar[Int]] {}
}

trait TestTC2[A]
object TestTC2 {
  given inst[F[_], A](using tc1: TestTC1[TestMatch[F][A]]): TestTC2[F[A]] = new TestTC2[F[A]] {}
}

summon[TestTC2[TestMatch[Foo][Int]]]

Output

-- [E172] Type Error: ----------------------------------------------------------
1 |summon[TestTC2[TestMatch[Foo][Int]]]
  |                                    ^
  |No given instance of type TestTC2[TestMatch[Foo][Int]] was found for parameter x of method summon in object Predef.
  |I found:
  |
  |    TestTC2.inst[TestMatch[Foo], Int](
  |      /* missing */summon[TestTC1[TestMatch[TestMatch[Foo]][Int]]])
  |
  |But no implicit values were found that match type TestTC1[TestMatch[TestMatch[Foo]][Int]].

Expectation

The implicit search should discover TestTC1.inst as a valid candidate for the using parameter of TestTC2.inst

[mrdziuban]

Sorry, never mind on this one, the summon part of my reproduction code above doesn't make sense. It's correct that there's no instance of TestTC1[TestMatch[TestMatch[Foo]][Int]] because that would be a TestTC1[TestMatch[Bar][Int]], and there's no case in the match type for Bar

There is some issue in my codebase similar to this, but I'm going to close this until I've minimized it. In the meantime, I'm confused why this compiles in Scala 3.4.2...