Apple id settings update infinite loop bug

Some time after i’ve changed email that was connected to my apple id, my iPhone asked me to update id settings for some services. All I have to do is enter password from id in settings again, but when i click it, there is my old email shown as current apple id. I cannot change it and any of my current or old passwords are not correct to pass this page. When I go to the only one alternative way on this page - “Forgot your password” button, iPhone automatically sets this old email as my actual apple id, again. I click “Continue” after what pops up a message: “..........@gmail.com isn’t an apple id”. I don’t need to do this process for correct apple id email, cause I remember all of my passwords, but I can’t make my phone to understand that this email doesn’t belong to any apple id.

So how can I fix it???

P.S. Sry for my language mistakes, I am from UA and didn’t have enough practice for a huge period of time.