Outlook 2016 doesn't accept password or app password

Hello everybody,

I am wondering if some of you are Microsoft 365 customers and are having issues with Outlook.

We are a company with approx. 6500 users and some of them have issues.

When we force a reconnect of the internet connection, then the issue is sometimes solved immediately, sometimes the reconnection has to be repeated several times.

That matches with some earlier posts, stating, that only some portion of the Exchange Online Cloud Endpoints are affected.

So we suspect that this issue here is also our issue but we are not sure.

I mentioned this issue in my previous comment. I am on Office 365 (I guess it's called Microsoft 365 now) for business. I have issue with this work account in addition to my personal Hotmail account. In my case, on around 1/23 when the issue started, I got kicked off and had to relogin with the 2FA process. In previous 2FA login, there is a checkbox for "...don't ask again for 365 days..." and it was checked but it appears that was ignored and had to relogin. After which while I didn't get the prompt for password on this work account, it was clear I was NOT getting email pushes or calendar/contact syncs. While working on my computer, I was getting emails frequently but not a whisper on my phone.... then I get a gush of emails on my phone like dozens and dozens all at once. I have been saying this issue impact business/paid accounts as well except it seem to cause sync issue more than password issue.

All I can say is Microsoft is A MESS lately... I left the US at the onset of this issue and I am about to end my 2-week oversea trip and the issue is still not fixed.

I had opened another thread in the German-language support forums ( https://answers.microsoft.com/de-de/outlook_com/forum/all/einrichtung-eines-outlookde-kontos-am-mobilen/0daa3368-8800-40af-b134-1509a6bda2ab) as I couldn't find anything on this topic at this time.

Interesting to me: even though this issue seems to have only occurred in late January due to this thread, I had a similar issue with my outlook.com account with Outlook on two different PCs (Microsoft® Outlook® für Microsoft 365 MSO (Version 2401 Build 16.0.17231.20194) 64 Bit) as of November/December 2023. I was prompted to enter my password (which I had only once before when setting up the account), and after signing in to my account, it got stuck in two popup windows, one of which said "Please wait" and the other just showed a white screen.

Even this issue is solved for me and my Outlook clients on my two PCs work well now, I have issues with my android smartphone connecting to just the same outlook.com account via EAS or EWS (the app I use supports both).

I cannot confirm that pressing the OK button several times or changing the Internet connection has solved the problem (today I switched several times between several WLAN networks and cell towers).

Funny thing is that on emClient forums they insisted and still do, that this is happening because Microsoft had announced that they plan to disable all basic authentication back in 2022 and now this change is taking effect for all servers.
Microsoft and basic authentication - personal outlook accounts - Announcement - eM Client
Is this in any way valid?

Basic authentication and even app passwords are disabled on Exchange Online accounts:

https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/deprecation-of-basic-authentication-exchange-online

But app passwords still exist on personal accounts.

For the love of anything holy.

This issues is marked as resolved again, saying implemented on 2 Feb. Considering I had this issue 2 mins before checking, and so many comments since 2 Feb, how is it marked as resolved? How can we get MS to reopen and actually fix it rather than saying days after it’s “resolved” when there are so many people still staying they have an issue