Some missed calls not showing up on phone logs, only in emails.

I am having an issue where missed calls are not showing up on our phone logs, but I will get an email showing a missed call. The phone never actually rings either. It shows they pressed the appropriate extension. Also, the phones never actually ring for these calls. Other missed calls show up. Is there some kind of filter perhaps blocking automated calls? It seems like when we call the numbers back, most of them go to recordings or it could be a switchboard at a big business however I noticed one from the dealership that I was expecting.