@beren1605 Welcome to the forum!
I just could log in without any problem to vault.bitwarden.eu.
Just to check some basics:
- did you use the correct email address?
- no typos in your email address and/or master password?
- I guess you intentionally used the EU server region? → if not, and your account is on the US server region, then the login only will work on vault.bitwarden.com for you
Here is a comprehensive list of other things you could consider and try: [Guide] "I can't login" - Some tips for login problems/issues