Issue:
SMS is still sending from the old SalesInvite number when I purchase a new one and select that as the default outbound number.
Reason:
Since we do not want to spam the leads with different SalesInvite phone numbers, the old leads will be stuck with the old default SalesInvite phone number unless you delete the old number. Only new leads added to your contacts will be getting SMS from the new default outbound number.
Suggestion:
We could remove the old SalesInvite phone number. That way all SMS will be sent from the new number bought.
If you want to keep the old SalesInvite phone number, another suggestion would be to assign the new SalesInvite phone number to the user and log in as the user to send those SMS. You could also assign the user in the Campaign Configuration. That way all SMS will be sent from the new SalesInvite number bought.