I have been noticing this error on twitter and earlier on facebook
New login alert
We noticed a login to your account @xxxx from a new device. Was this you?
New login
Device: xxx
Location*: xxxx
When: Wednesday, January xx, 2020 at x:xx PM xxx (3 minutes ago)
*Location is approximate based on the login's IP address.
If this was you
• You can ignore this message. There's no need to take any action.
If this wasn't you
• Change your password now to protect your account. You'll be logged out of all your active Twitter sessions except the one you're using at this time.
The users seems to still be getting this message even after changing their password . Location shows the correct user location. But the error?
update 4.2.2020
In a statement published today, Twitter disclosed a security incident during which third-parties exploited the company's official API (Application Programming Interface) to match phone numbers with Twitter usernames.
https://www.zdnet.com/article/twitter-says-an-attacker-used-its-api-to-match-usernames-to-phone-numbers/