Once you log in to the vidIQ Extension make sure you log in to YouTube with the SAME channel(s) authenticated in your vidIQ account.
💡 Example:
In your vidIQ account enterprise@company.com you added two channels: "Channel 1" and "Channel 2". You must log in to YouTube with a Google account that can access "Channel 1" and "Channel 2". That being said, channels in your vidIQ account and Google account that you are using to log in to vidIQ must match.