Weird phone call after superday

Had a superday around two weeks ago and felt pretty good about it. Two days ago, I got an early morning call from the office phone number. I picked up but the person on the other end never said anything and hung up super quickly, I barely even had the chance to say "hello?" so I don't even know who was on the other end. I called back but the main phone number just redirected to the front desk, who told me I should wait for a call back since I didn't know who made the phone call. I emailed the recruiter about it asking if there was anything I should do, but never heard back. Is this a bad sign? I'm honestly worried they made a mistake or smth