TypeFamilies don't seem to play with LIberalTypeSynonyms

I'm trying to do some type level programming and want to use type families, but also LiberalTypeSynonyms to allow passing in a type level identity:

The following works:

{-# LANGUAGE LiberalTypeSynonyms #-}

type Id x = x

type Generic t (i:: * -> *) = i t

foo :: Generic Int Id
foo = undefined

However, replacing Generic with a type family does not work:

{-# LANGUAGE LiberalTypeSynonyms #-}
{-# LANGUAGE TypeFamilies #-}

type Id x = x

type family Generic t (i:: * -> *)
type instance Generic Int i = i Int

foo :: Generic Int Id
foo = undefined

Hopefully I'm not over looking anything, but I can't see why this doesn't work.

Trac metadata

Trac field	Value
Version	7.0.4
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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