I am having the same difficulties, and it's giving me a headache. The only workaround was to change the authentication method to "Normal password", and enable t

I am having the same difficulties, and it's giving me a headache. The only workaround was to change the authentication method to "Normal password", and enable the "Allow less secure apps" setting on the Gmail account. And that's a major PITA since I have 40-ish Gmail accounts. (Why so many? I tend to separate my different concerns for privacy and security reasons.)