The One GVA - Speakers Not Able to Make Voice Calls
Since the latest Google update, Google Assistant on 3P smart speakers will no longer be able to make a voice call to a landline or mobile number on the carrier network. Voice-over-IP calls will continue to work. This is due to the ongoing infrastructure improvements.
If a user tries to make a call to a mobile or landline, Google Assistant will say “Sorry, I can’t make calls yet,” or in some cases “Something went wrong.”
Users can still use the Assistant on the phone, watch, etc. to make calls. The change is specific to GVA speakers.
Follow this link to see Google's official statement: https://support.google.com/assistant/answer/9071678
"In December 2022, Google-supported phone calls from non-Google speakers and smart displays may no longer work. VoIP like Duo will work normally."