Problem signing in
I have a new iMac but can't sign in with apple id despite being able to on other devices, eg iPhone.
iMac 21.5", macOS 10.15
Where can't you sign in? If this is when initially starting the computer, have you tried using the user ID and password?
If you continue to have problems, you are entitled to 90 days of telephone support from Apple. Try contacting them.
Work through the screens to get an email or chat option.
Apple Support by e-mail or chat