Primary Constructors for Handlers

[Ieuan81]

Are Primary Constructors, introduced in C# 12, supported when writing Handlers?

I have tried using them and am getting some odd behavior whereby my dependency injections e.g. _dbContext show as null in Visual Studio yet appear to exist despite that (method calls don't thrown NullReferenceException).

public class CreateThingy_CommandHandler(ApplicationDbContext _dbContext) : IRequestHandler<CreateThingyCommand, ThingyDto>
{ 
    public async Task<ThingyDto> Handle(CreateThingyCommand cmd, CancellationToken cancellationToken)
    {