Apologies in advance for the complex issue description. I am at my wits end and, as anyone who has ever tried knows, getting any meaningful Google help/support is pretty much impossible.
-1) This is a very recent (as in just this week) issue; I have been using an installed version of Outlook client to access Gmail on my desktops forever, with several Gmail addresses hooked up to it.
-2) The only account that is experiencing an issue is my main use/primary account. Technically speaking, though, there is no difference between how these accounts are set-up (AFAIK), either in Outlook or out on Gmail, or in how they are used…
2.1) …with the only exception that my primary email (the one I am having an issue with) is also set-up on my mobile phone (with a non-Gmail client). It does not have any issues sending/retrieving email for this account. I don’t think this is diagnostically relevant, but it is the only difference I can think of.
-3) I have always set up these accounts with POP3; I’m not interested in IMAP. I DO have “less secure apps” toggled on for this, and all, of my Gmail accounts.
-4) What I experience is some sort of security/authentication issues…it’s probably not diagnostically relevant, but Outlook responds with:
But the credentials entered are correct and reentering them manually does not help.
-5) I can “solve” the issue in the very short term (like for a matter of minutes or one auto send/receive cycle?) by using this link: https://accounts.google.com/DisplayUnlockCaptcha. It “works” on any browser, as in Chrome, Edge, or Firefox, and I can always sign into my Google account via browser with no issue, i.e. this has to do with Outlook specifically (it would seem). Note: it almost never presents a “captcha” thing…?
5.1) The DisplayUnlockCaptcha URL even “works” if I use it on DMS Jump server; I can then immediately perform a successful “Send/Receive” operation within Outlook on my desktop. But in both cases, the security/authentication failure, via the Outlook dialog above, reoccurs very shortly thereafter.
-6) I do have a VPN (Windscribe) installed on both my desktop and within my main (Firefox) browser. But, again, I have had it installed for a while now, and I have other email accounts that work just fine.
Any thoughts or suggestions?