Cannot log into my Apple Account on Mac, but can on my iPhone and Safari.

I've tried endless phone calls and Apple Store visits and still cannot reach the bottom of this issue.

I can log into my Apple Account if I go on Safari or on my iPhone. On my Mac, I cannot log into it on any service (Apple ID in system preferences, iMessage, FaceTime, App Store, etc). I know for a 100% that my log in credentials are correct because I can log onto it elsewhere. It tells me things like "this Apple ID is not valid or not supported", "An Unknown Error Has Occurred", or that my "Username or Password are Incorrect" (they're correct!).

I have tried:

• • using a more recent Mac from 2022
  • Deleting adblocker (my only third-party extension installed)
  • trying multiple different wifi servers as well as my hotspot
  • reseting my password multiple times
  • deleting all from my "Internet Accounts"
  • Reseting my devices over, and over, and over...
  • Likely a lot more I'm not recalling.

One thing I saw suggested was that perhaps I am not being prompted with the opportunity to plug in a two-factor authentication code (which I am prompted to do whenever I log in on Safari or my iPhone), however I'm not sure how to get one of these codes sent to me when trying to log in on the above mentioned places on my Mac.

Does anyone have any other suggestions? HELP!!!!