In the past, I've asked Support to delete all devices from my old login account (a non Gmail account) so I can start over since I don't have access anymore to that non-Gmail account (it was a @domain.com account). And HP Support did delete all devices from my old non Gmail account. Once done, I logged in using the Sign in with Google and use 1 of my Gmail accounts to login. Much easier. Once in, I proceeded to re-add my devices and continue to provision with 3rd party Services (I have several) and it worked. That was under a OBi202 device.
And now that the OBi2xx series are EOL, I've move over to the OBi302 instead since I am not using consumer Google Voice Service anymore. But I had to ask Support to "associate" both the OBi302 device to the same Gmail account login. Once done, I simply re-provisioned back to same 3rd party accounts and done. All calls successful, same as before but under OBi302 device now.
If you have 3rd Party Service Provider Account(s), such as Callcentric, or Ringcentral, or Phonepower, etc....I highly suggest moving over to OBi300 or OBi302 but use a Gmail account at the Sign in with Google to login. Let HP Support people associate your login (Gmail account) with your OBi300. Again, much easier. Good luck.