That is indicative of the password being incorrect. Thunderbird just reports back to you after sending the password to the server. Some email hosts require special 'app' passwords for use in an email client. Maybe, if you provide information on the domain name of the email account, somehone may have suggestions.

Thank you David.

That was the cause when starting to use the new server. It has been corrected with new, saved passwords. And the issue persists.

If you are unable to access email, the server still isn't happy with the password. I don't know if it will help, but you could remove existing passwords and try again to see if that helps. the current passwords are in settings>privacy&security. By clicking saved passwords and then show passwords, you could highlight rows related to the account and delete them. If that isn't helping, you could exit thunderbird and move the cert9.db and key4.db files elsewhere and restart thunderbird. I suggest moving, not deleting, in case you determine needing to move them back - they have certificate data.