Visual Studio Copilot cannot retrieve files by tag

[xperiandri]

Describe the bug

I've given Visual Studio Copilot links to files:

• https://github.com/dotnet/fsharp/blob/v13.9.300/src/FSharp.Core/array.fs
• https://github.com/dotnet/fsharp/blob/v13.9.300/src/FSharp.Core/array.fsi
  but got
  I couldn't retrieve the array.fs or array.fsi files from the specified repository or branch. You may need to verify the repository structure or provide alternative links.

When I provided

• https://github.com/dotnet/fsharp/blob/release/dev17.14/src/FSharp.Core/array.fs
• https://github.com/dotnet/fsharp/blob/release/dev17.14/src/FSharp.Core/array.fsi
  it successfully downloaded them

Affected version

Current remote

Steps to reproduce the behavior

1. Ask to compare your code with the files above
2. See output that it caanot retrieve files

Expected vs actual behavior

Files are retrieved the same as from a branch

Logs

[CopilotSessionProvider Information] Request content: "Check if I have parity in functions defined in F# `Array` module. And all XML comments present and correspond.
Use links below to verify
* https://github.com/dotnet/fsharp/blob/v13.9.300/src/FSharp.Core/array.fs
* https://github.com/dotnet/fsharp/blob/v13.9.300/src/FSharp.Core/array.fsi "
[CopilotSessionProvider Information] Begin sending message (ConversationId:dec6fe10-adf6-4978-85f8-6016a76b04ff, CorrelationId:802c79db-f27e-4d5d-89e4-b6a78c528a3f, MessageId: 73156bd6-90d9-44b8-8a6f-2b436bb41a54)