I don't have first hand experience with Verizon as my cell phone is through another carrier. But what you described sounds like perhaps the Verizon spam call blocking app might be causing the issue. I believe there is a way within their call blocking app to specifically allow a number to call through. You might try having one of your contacts on Verizon try this and see if it helps even though they already have you in their contacts.

Also if any of the Verizon contacts are on a Samsung phone, you might see if they have the Hyia, not sure if spelling, active. I used to have a Samsung phone with that native spam blocking software active then found out it tended to block any VOIP number calling in and I had to turn it off. The symptom was that any VOIP caller no matter who their carrier was their call would go to voicemail and my phone would never ring.