iPhone X Ring Volume Low

Why does the ringer volume not increase when I attempt to use Ringer Up volume button or in the Settings?

Also, why does the ringer volume go very low after the first ring and we are not able to increase the volume so it stays louder?

1) When attempting to use the volume up button to increase the Ringer volume it increases the Volume for the sound but NOT the Ringer.

2) When I receive a call the volume is low and goes even lower on subsequent rings.

TROUBLESHOOTING:

I would change the ringer to/from silent then press the up button in an attempt to increase the ringer volume but it only increases the Volume for the sound (ie; music) but NOT the Ringer. The Ringer screen would pop up but it's immediately replaced with the Volume screen.

I went to Settings>Sounds & Haptics>Ringer and Alerts and increased the slider button to max (the sound would ring very loud). I also turned ON Change with Buttons (*the volume of the ringer and alerts can be adjusted using the volume buttons) but the Ringer volume would still be low when I would make a test call.

I spoke with 3 other iPhone X owners and when we performed a test call they, too, had the same issue.

UPDATE: After adjusting and readjusting the volume in the Settings for the ringer and turning the ringer ON/OFF on my iPhone X it suddenly began to ring normally with an incoming call. HOWEVER, the other 3 iPhone X's still have the very low ringing issue when a call comes in despite trying to fiddle with the settings as I did.