Calls go to voicemail even with good cell service - iPhone 16 Pro

New iPhone 16 pro. Incoming calls frequently, but not always, go to voicemail even though I have 3 bars of cellular service (Verizon). Never had this problem before with previous iPhones or Android phones. Same location (my living room). My wife has the same problem with her iPhone 16 pro max. We are both missing numerous important business calls, and this is completely shocking and unacceptable. I have read everything online about this and tried all of the suggested fixes including the following:

1. Check to see that the Silent switch is not set to ON. Silent switch is located on the Top Left Sideof your iPhone.
2. Open Settings ➔ Sounds & Haptics ➔ Ringer and Alerts : Make sure this is not set to OFF or too Low. Set Change with Buttons to OFF. Below that Make sure that there is a Ringtone selected.
3. Check to see that Silence Unknown Callers is set to OFF. Open Settings ➔ Phone ➔ Silence Unknown Callers : Set this to OFF
4. Make sure that a ringer sound is assigned. Open Settings ➔ Sounds & Haptics ➔ Ringtone : Ensure that a Ringtone is assigned here.
5. Check to see that Do Not Disturb is set to OFF. SWIPE DOWN from the TOP RIGHT CORNER of your screen. This will reveal the CONTROL CENTER. Find the FOCUS button (should be highlighted in white if Do Not Disturb is ON) and Tap on it. This should turn OFF Do Not Disturb.
6. If all of the above is OK on your iPhone then Try and Force Restart your iPhone EXACTLY as shown below and see whether that resolves the issue:

• Press and quickly release Volume UP button
• Press and quickly release Volume DOWN button
• Press and Hold the SIDE button until an Apple logo appears and then release the Side button (Can take up to 20 seconds. (DO NOT release Side Button when invited to Slide Power OFF). 

In addition to the above, I tried clearing the "system data" storage as suggested in another thread. Nothing.

Additionally, I have turned of the Focus sharing across devices on all devices. Nothing.

None of these suggestions worked. My wife and I excitedly spent $3,400 on new iPhones. Now, we are both losing untold thousands because of this issue. She lost a real estate deal just yesterday because her client couldn't get through to her. I received a call from a sales client yesterday who told me he constantly gets my voicemail and that he needs a more reachable sales agent. That account is worth probably around $8,000 in commissions to me.

My research tells me that this is an ongoing problem for this model. Does anyone have a resolution?