Magicjack doesn't get incoming calls all of a sudden

I just recently switched over to an xFi gateway instead of using my own router on xfinity Internet. I've been using magicjack for about 15 years and been with xfinity for over 2 years. Current one is magicjack home. All of a sudden, shortly after switching to the gateway modem, people are receiving messages that the magicjack customer is unavailable. We can make calls out but calls in are not getting through. I tried a test by calling the home phone from my cell phone - while in the house - and it went through. I just happened to think, however, that my mobile phone was most likely using Internet to make the call - and - I was on the same network as my magicjack!

I heard/read somewhere that a port could possibly have been blocked by my gateway/xfinity and that's why it's not working? I have NO clue where to go from here. It's keeping annoyance calls away, but it's doing the same for necessary calls, also!

Any help would be appreciated. Thank you in advance!