ICloud login issues

I am able to login into iCloud through a web browser but when I setup my phone and login into my account, I am unable to log in . For the first time login during the day or after resetting password, I get an authorization codes on my other devices but when I use the code and proceed login then an error message pops stating Verification Failed , the username or password is incorrect. Upon further attempts it says the Appleid is locked for security reasons and needs to unlock . I unlocked it by resetting password but again , the same issue repeats. I have been chasing this issue to get resolved since February but the engineers @ apple are struggling to resolve it. Has anyone come across this weird issue? I had data of great importance to me in my backup but I can’t restore my phone using that iCloud account though I am able to login here through the same account to post this issue.