@jongorama Welcome to the forum!
If you already checked if the master password input was correct, the email address was correct and the server (US v. EU) was correct, next thing to consider would probably be, if you have any problematic special characters in your master password - and if there was some kind of auto-correction at play (e.g. inserting an unwanted uppercase letter, space bar or quotations mark conversions are also popular).
Those two things are described in more detail here: [Guide] "I can't login" - Some tips for login problems/issues so I would recommend to check that. If that doesn’t help, you could also check the other points in that guide.