Move Type refactoring removes generic type declarations when exist non-generic with same name in same named file

_This issue has been moved from [a ticket on Developer Community](https://developercommunity.visualstudio.com/t/Move-Type-refactoring-removes-generic-ty/11108643)._

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[severity:It bothers me. A fix would be nice]
I don't know what exactly raised that problem - Roslyn, Intellisense or just Editor.
What happened:
1) I have created some interface A as file A.cs, all fine
2) I have created some interface B<TSelf> and B<TSelf, T> : B<TSelf>, also in A.cs, all fine
3) I have created some struct C : B<C> and C<T> : B<C, T>, also in A.cs, all fine
4) I moved to separate file B.cs interface B, all fine (RMB, Quick actions and refactoring, Move type to B.cs)
5) I moved to separate file ??? interface B<TSelf, T>, no errors, but B<TSelf, T> just disappear and wasn't in B.cs or A.cs
6) One-by-one as in 5, but for C.

Ctrl+Z in A.cs returned me generics, so there's no just deleting, but that problem stops my coding for a few seconds.

```csharp
namespace Test;

public interface A<T1, T2, T3>
where T1 : B<T1>
where T2 : B<T2>
where T3 : B<T3>
{/*...*/}

public interface B<TSelf>
where TSelf : B<TSelf>
{/*...*/}
public interface B<TSelf, T> : B<TSelf>
where TSelf : B<TSelf, T>
{/*...*/}

public struct C : B<C>
{/*...*/}
public struct C<T> : B<C, T>
{/*...*/}
```

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### Original Comments

#### Feedback Bot on 6/17/2026, 07:14 PM:

Based on similar issues resolved with Microsoft in the last 6 months, the following can help resolve this issue faster.

If not already included, please provide:

Detected: OS: 10.0.26200.0, VS: Insiders [11904.113], Product: community-2026, Project type: C#

Please share:

• Whether this reproduces in a brand-new simple C# solution, or only in the current solution/file.


• The exact steps that trigger the issue after using Move type to file, especially for the generic interface/struct declarations.


• Whether the moved type is actually removed from the source file only, or whether it appears in the destination file and then disappears.


• Whether the issue happens every time or only sometimes, and whether it still happens after restarting Visual Studio.


• If possible, a short screen recording showing the refactoring steps and the result.

#### Feedback Bot on 6/18/2026, 10:23 AM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

Reproduce the problem in a simple C# solution by placing the generic and non-generic B and C declarations in one file, then using the Move type to file refactoring. Start by tracing the refactoring behavior for declarations with the same name but different arity; done means the generic declarations remain in the source or destination file after the move.

Written by the indexing model from the issue text.