I've used the same Google account for both OBI and GV. The other day I realized I had VM, but wasn't able to access it. I tried logging into GV and my number was nowhere to be found. Tried to recover it and it validates I have the correct email address, but never sends me the recovery link.
Next step was to log in to OBI which I haven't done in about two years. It's like my account is totally obliterated, like it never existed. I set it up again with the same gmail address and the phone number is also not present.
I did a reset and now I can't call out or receive inbound calls. I ended up setting up a whole new GV number just to get the phone working again, but still want my old number back (had it for 15 years).
If you call the old number it still has my VM greeting, so I know it's not totally lost.