GrandCentral Ends Calls on the Hour?

Two days in a row I’ve been on a call that I received through GrandCentral. Both times, the call has been disconnected right as the hour turns: from 2:59 to 3pm Mountain yesterday and 10:59 to 11am Mountain today.

Yesterday I was on an IP phone and the other party was on a hard line, today I’m on a hard line and the other party is on a cell phone. The common element is I received both calls through my GrandCentral number.

Anyone else experiencing this? I’m curious to see if this continues to happen.