Childminder issues

My son (age 2.5) started with a childminder 3 months ago. He goes in fine and seems happy and excited but I think he gets told off a lot and comes home super stressed. He had previously been in a nursery and seemed very relaxed- now his behaviour is often bad. I’m not sure what to do as we can’t really change things now but I’m concerned he might not get used to it and I’m causing him- and her stress? I’ve spoken to her about things and she is sometimes very helpful and other times seems quite off. I don’t know what to do!?