Services not recognizing phone number

More than 10 years ago, I used a google voice number for most things, forwarding calls to my Verizon number which I rarely used or gave out.

When signing up for services that asked for a mobile phone number (like Venmo), the google number would often get rejected as a VOIP number and not a mobile number. Fair enough.

Last December, I finally ported the number from Google Voice to Verizon. It is now a fully functional mobile number on the Verizon Wireless network, and is no longer a Google Voice or VOIP number.

However, most services still reject it as “not a real mobile number”. Whatever third party services they use to validate phone numbers still see this number as a VOIP number, even though it is not any longer.

How do I go about “legitimizing” this 100% mobile number for use with various account services?