Can't go to implementation, definition or reference

Type: Bug

Environment data

dotnet --info output:

.NET SDK: Version: 8.0.401 Commit: 811edcc344 Workload version: 8.0.400-manifests.6c274a57 MSBuild version: 17.11.4+37eb419ad

Runtime Environment: OS Name: Windows OS Version: 10.0.26100 OS Platform: Windows RID: win-x64 Base Path: C:\Program Files\dotnet\sdk\8.0.401\

.NET workloads installed: Configured to use loose manifests when installing new manifests. There are no installed workloads to display.

Host: Version: 8.0.8 Architecture: x64 Commit: 08338fcaa5

.NET SDKs installed: 6.0.425 [C:\Program Files\dotnet\sdk] 8.0.400 [C:\Program Files\dotnet\sdk] 8.0.401 [C:\Program Files\dotnet\sdk]

.NET runtimes installed: Microsoft.AspNetCore.App 6.0.33 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 8.0.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 6.0.33 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 8.0.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 6.0.33 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 8.0.8 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found: x86 [C:\Program Files (x86)\dotnet] registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables: Not set

global.json file: Not found

Learn more: https://aka.ms/dotnet/info

Download .NET: https://aka.ms/dotnet/download

VS Code version: 1.93.1 C# Extension version: C# 2.45.25; C# dev kit 1.10.18

Issue Description

Can't go to implementation, definition or reference. It shows "No definition found", "No implementation found" or "No reference found". It used to be able, but recently it can't go to implementation.

Steps to Reproduce

Git clone https://github.com/stakira/openutau , and open the cloned repo folder in vscode.
open OpenUtau\ViewModels\LyricBoxViewModel.cs
On line 19 [Reactive] public UVoicePart? Part { get; set; }, right click UVoicePart and click "Go to definition"

Expected Behavior

Vscode opens OpenUtau.Core\Ustx\UPart.cs where UVoicePart is located.

Actual Behavior

Logs

vscode extension logs.zip

dotnet / vscode-csharp