Apple ID password

When I sign in for something that needs my Apple ID password, I put it from my password list. It says I have the wrong password and need to change. I go through that & get a message it’s been successfully changed. And it shows up changed on my list. Then I go to set up an app specific link for my mail sorter program and it has me put in my Apple ID password to do that. So I put in the new one. And immediately I get a locked screen telling me I need to reset my password. Which I’d just done. So far I’ve been through this loop six times & can’t figure out what my problem is.