Okay, now that I posted my question I’m one step closer to figuring it out.
I had to recently change my Gmail password, and I enabled 2-step verification in the process. From what I gather from this link (https://support.google.com/mail/?p=InvalidSecondFactor), that might be the issue causing the plugin’s inability to communicate.
How can I fix that while keeping 2-step verification? Is that possible?
Thanks,
Valerie