It's possible that Visual Studio is not properly configured to connect to your Azure subscription. Here are some steps you can try to troubleshoot the issue:
Ensure that you are signed in to Visual Studio with the same Microsoft account that has access to the Azure subscription.
Check that you have the latest version of the Azure SDK for .NET installed. You can download it from the Visual Studio Marketplace or from the Microsoft website.
Try clearing the Visual Studio cache by deleting the "%LOCALAPPDATA%\Microsoft\VisualStudio<version>\ComponentModelCache" folder, where <version> is the version of Visual Studio you are using.
Verify that you have selected the correct Azure account in Visual Studio by going to "Tools" > "Options" > "Azure Service Authentication". Under "Accounts", make sure that the correct account is selected.
If none of the above steps work, try resetting your Visual Studio settings to default. You can do this by going to "Tools" > "Import and Export Settings" > "Reset all settings".