Ask HN: Is Gmail's “Send mail as” feature not working for you?

As of this morning, I've been getting the following error when I send mail using the Gmail "Send mail as" feature: > Message not delivered > You're sending this from a different address or alias using the 'Send mail as' feature. The settings for your 'Send mail as' account are misconfigured or out of date. Check those settings and try resending. Is anyone else facing this? I have two factor authentication enabled, so in order to use this "Send mail as" I have to generate an App Password. I tried deleting and recreating the App Password and it works for around an hour then stops working again. Curious if it's just my account or if this is happening for others too?