Why does my password not work any more

This morning when I wanted to log in Twitter reported that my user and/or password is unknown. I have not changed anything. However, I requested a new password and afterwards I could log in again. Somehow my password was changed. between yesterday and this morning. How can something like this happen? I have used a service called Tweeterspeed.com which I cancelled after a few days as they advertise on my personal Twitter thread. I don't know if this might be part of the problem. I am concerned that my Twitter user authentication was somehow compromised. Please look into this.
ChristSk8Board