All Google Authenticator 2FAs gone

Yeah, everything was running smooth till one day I decided to add a new 2FA on Google Authenticator while offline. Later when I connected back online, Google Authenticator auto-synced, but darn it, all the previous 2FAs vanished into thin air. Only that one I added offline was left. Lesson learned - gotta backup those 2FAs regularly on your hard drive, just in case.