After you file

I keep getting 4464C letters every day. I called today and she said she only sees two that were sent. For anyone who gets multiple letters- the 60 day review starts on the most recent letter received. I’m losing my mind here because I’m already at the 30 day mark from the first letter and then got one today- starting me back to 60 days. She also said she can’t tell me what the issue is. :(