[NETSDKE2E][Green] Error MSB4057 'The target "ResolveProjectReferences" does not exist in the project.' occurs after switching single TFM to multiple TFM.

REGRESSION INFO:
Also repro in C# DevKit public Prerelease 3.33.194

INSTALL STEP
OS: windows x64/Linux x64
Install the SDK 10.0.400, SDK 9.0.318
Install VS Code stable - 1.138.0
Install C# Dev Kit V3 Sept release 3.40.201, includes C# 2.151.28

REPRO STEPS

1. Click the Create .NET Project button to create a Console app project (e.g. ConsoleApp1).
2. Expand C# Project Details from the Explorer sidebar.
3. Open csproj file, switch from single TFM to multiple TFM (e.g. net10.0;net9.0)
4. Press "Ctrl+S" or build the project.

Expected
Error MSB4057 'The target "ResolveProjectReferences" does not exist in the project.' occurs in the "Problems" window.

Actual
No error occurs.

Note:

1. If you DON'T expand C# Project Details in step2, the bug is not repro.
2. After close and re-open the VS Code, the error disappeared.

Log:
csdevkit-logs-2026-09-16T02-43-26.zip

Reproduce the issue through the Create .NET Project flow, expand C# Project Details, then change the csproj from one TargetFramework to multiple TargetFrameworks and build. Start by reviewing the attached csdevkit logs and the behavior around the C# Project Details view. Done means the multi-targeting change no longer produces the reported MSB4057 error, with the expected and actual behavior clarified.