I have an OBI1022 with all six lines configured for google voice numbers. My understanding is that when a call come s in on a lien that is in use its supposed to go to the first unbound line (In this case line 7) and ring that.
Mine doesn't do this - it comes in on the same line I am already talking on as a "call waiting" second call on the same line. If I disable call waiting the call does not come in at all.
I want inbound calls on busy numbers to go to those last four lines like they are supposed to. I can't see what I'm doing wrong.
You're describing a "hunt group". Google Voice does not support that feature at all. GV is not a business telephone system. It's intended for individual, consumer use. Obtaining six lines for commercial use is a violation of Google's acceptable use policy; you may find that your service gets suspended at some inopportune moment.
Use one of the many SIP VoIP service providers, and sign up for as many inbound phone numbers (DIDs) as you need. You can easily set up either a hunt group, and all the other typical features of a business telephone system.