Don't remove it from the Obitalk portal. That is what I did along with a hard factory reset on the Obi device. After struggling to add it back to my Dashboard, now it won't provision at all. All 4 lines including GV, other VoIP provider, local Asterisk, can't be configured through Obitalk at this time.
I was able to restore using an old backup though the local web interface of Obi device. Some lines work with exception of the GV lines which sit at Service Not Configured. Even though everything looks like its there in Service Providers and Voice Services, it appears GV can't restore through a backup correctly.