We have a receptionist who transfers calls to my extension during the day. When she does this my cell phone rings at the same time as my office phone. When we are after hours the office phone still rings but my cell does not. Settings all seem correct. What are we doing wrong?

We have a receptionist during business hours who sends calls to my extension. My cell phone gets these calls simultaneously as well DURING THE DAY. When in After Hours, calls still hit my extension but do NOT go to my cell phone. Any ideas what could be wrong? Settings all look correct.