Problem with Facetime Audio feature ringing to several phones...

I currently have 4 iPhones & 2 iPads on our iTunes account. I had to change my Apple ID password recently, which required all devices to have to log back in. We all have iMessage & Facetime and went to settings to set (check) our own number to direct what calls & messages we shared, which is only between 2 of iPad/iPhone sets. All phone numbers are individual & set that way...however, my sons phone will receive Facetime Audio calls if anyone is calling me or my husbands phone number as a Facetime Audio call ONLY. He won't receive phone calls or the video Facetime calls. Even weirder chain of events when my husband called me later as a regular voice call, it showed call ID as if it was coming from my sons phone. This has only happened since I updated my password. I've tried logging out of iCloud on his phone & logging back in, turning off Facetime & back on...making sure all the numbers were correctly marked in all devices and nothing works...but again, it's ONLY when using the Facetime Audio feature and just with his phone connecting to mine & husbands., not the 4th phone on account. Anyone else experience this?