Cannot assign to byref-returning type functions

[IS4Code]

When a let-bound value with type parameters is of a byref type, assignment to this value incorrectly requires a byref value.

Repro steps

type Storage<'T> =
  static let mutable value = Unchecked.defaultof<'T>
  static member public ValueRef = &value

[<GeneralizableValue>]
let cached<'T>: byref<_> = &Storage<'T>.ValueRef

do
  cached<int> <- 1
  ()

Expected behavior

The assignment succeeds and results in a modification to Storage<int>.value.

Actual behavior

The assignment fails to compile:

error FS0001: This expression was expected to have type
    'byref<int>'    
but here has type
    'int'

The compiler can detect that the value is mutable (otherwise there would be an error about assignment to non-mutable location), but a wrong type is required.

Known workarounds

Turning the value into a normal function (i.e. let cached<'T>() and cached<int>() <- works fine.

Related information

It seems this issue affects all uses of cached<'T> that involve byrefs or assignments, for example:

do
  let mutable r: byref<_> = &cached<int> // Expecting a 'byref<byref<int>>' but given a 'inref<byref<int>>'

  let mutable a = 1
  a <- cached<int> // expected to have type 'int' but here has type 'byref<int>'

  cached<int> <- &a // Type 'byref<byref<int>>' is illegal because in byref<T>, T cannot contain byref types.

Environment: https://sharplab.io/#v2:DYLgZgzgPgLgngBwKYAIDKMD2AnAhgcyQB4ByAFQD4UBeAWACgUUIZcYBLAYxWCRhQC2AV1YAjXigBuuYENTUUAVQB2nABZJOAayQATAHS6kYXEOBYwpSgyYs2XQUgGik2FAiHiHANRlyASsY0KABk0rJIDAwA2kQA4kjKrjLsAF644ki+ERQAugy8/Jy46npWFCAoonDYxkQA+lQKIRg4BMTkFPrZAcZR9LqYNijFpbpE7MowVEQAtCgAjMMAFACUDEA===