@inject context user returns null with multi-guards

My Lighthouse's (v5.0.2) default guard is 'web', but I use an 'admin' guard also.
Default guard context works properly in any case, but when I need to use admin's context – it returns null.
(Whereas admin guard works correctly like a guard: it protects field and mutations as expected).

There is a mutation example:
addNote(text: String!): Note! @create @inject(context: "user.id", name: "admin_id") @guard(with: "admin")

I've tried to create a custom mutator and it possible to get an access to admin's context via
$context->request()->user();
(Whereas for default guard $context->user works also)

But if I have a lot of simple mutations like @create, @update, etc., do I really need to create multiple custom mutator methods in this case instead of just using @inject directive?

And another problem: if I need to give an access to the same mutation to multiple guards, I do need to write it twice (or more) and name differently.

Do I misunderstand something?

Many thanks!

Start by reproducing the mutation using @inject(context: "user.id") with the admin guard, then compare its behavior with @guard(with: "admin") and the request user available to a custom mutator. Done means the expected behavior for multiple guards and @inject is established, with the relevant mutation cases covered by tests or clearly documented.