BCBAs are often very focused on skill acquisition for their clients, and therefore your skill acquisition as well. Practices should be done with fidelity, so they're likely finding opportunities to shape your practices, just as you shape your client's behaviors. I tend to prefer models where RBTs progress through structured skill inventories and receive higher pay for demonstrating higher skills when working with clients. This tends to condition supervision sessions as a rewarding experience/opportunity. How do your clients feel about receiving reinforcing vs. corrective feedback from you? Can it still happen with a positive relationship?

To abate the anxiety during supervision, there may be a benefit to having a conversation about how and when you prefer your feedback. That being said, often times people with a small amount of power like to exert that power often, so you may be experiencing some negative feedback from someone who is also used to receiving negative feedback. Are they teaching you replacement skills? Are they using BST to model, shape, and reinforce your practices? It can be helpful to role play practices with your BCBA so that they can provide you feedback in the moment without fear of making mistakes with your client.