You might audition for the same series numerous times.
It’s common to wonder why they keep bringing you in and why you don’t get cast.
If you keep getting auditions for a particular series it means the producers and casting want you on that show. They keep a list of actors they want to use. You’re on that list.
As always, they have their taste as to who they want for each role. The type they need to fulfill the job of that role in that episode. You might be too tall, too short, young, old etc.
It’s not your acting - if your acting wasn’t good you wouldn’t be getting more auditions.
The hard work of auditioning is part of the protocol of being an actor. Hopefully, knowing the show-runner likes you helps you relax.
A problem with the protocol is that no one ever tells you they like your work.
Still, it's a positive thing you keep auditioning for the same series.
The producers like you.
You’re on their list.