Really weird moment with HR

So I interned with a company last summer, and got a return offer to come back this summer. I signed their offer as, obviously, the deadline they had to sign wasn’t very long. I’ve been applying and in

So I interned with a company last summer, and got a return offer to come back this summer. I signed their offer as, obviously, the deadline they had to sign wasn’t very long. I’ve been applying and interviewing with other companies, and got an offer with another company that is a larger tech company and pays $12 more. I signed with that company, so I would need to renege the other offer from my old internship. It was a little awkward considering I knew people who worked there from my internship, but I sent the email to my HR person explaining I couldn’t pass up the other opportunity and that I was going to renege. However, instead of just giving an email back, she called me almost instantly, 2 minutes after I sent the email. I didn’t pick it up because I was lowkey scared, but she left a voicemail saying she wanted to touch base and know more about why I chose the other company. I considered ignoring that, but I thought that if I called and explained a little, I could salvage a little of the relationship with her company. After an hour or two I called her back. When the call started, I apologized for missing the previous call, but she completely ignored my apology and asked to know more about the other company. I told her it was tech company and a little about my role. She asked what company it was, but I wasn’t really comfortable with saying. I simply said “I don’t really want to get into specifics of what company it is, but it’s a larger tech company.” After I said this, she said she was going to “await an announcement on my LinkedIn” so she could find out what company it was. I was really confused by that, and towards the end of the call she said again she was “looking out for a post or update on my LinkedIn,” even after I said I wasn’t really comfortable sharing the company. After words she said have a good day, I said thank you, you too, and she just said “you’re welcome” and hung up. I know that she was probably upset I reneged, but I feel like her blatantly not respecting me wanting to keep the company a secret, AND pretty much admitting she was going to stalk my LinkedIn for the answer was really weird. She said she needed the information for “data,” but it was still very weird to me. For additional context, when I interned at this company last summer, I was originally going to graduate early, so I was hoping to get a FT return offer from them. They did not give it after making me wait until December. Their company is tire to the government, so wit the government shutdown and everything I understand how the could have experienced sudden changes and delays. However, they said they would try reaching out if other opportunities came, but they obviously never did. I reapplied to their internship in April and got a return offer for the internship when I reapplied. I don’t know if I’m being outlandish but I don’t understand why they would care so much about me reneging and be so upset and, again, blatantly weird imo when they didn’t give me a return offer and didn’t contact me for months. I know companies usually only care about you when you’re in their pipeline, but I found the whole thing very weird and I’m wondering if this is normal or if it was a strange encounter.