Suddenlink mail password not working on Mac Mail

I recently changed my password on my Suddenlink account. When I did, Mac Mail logged me out of my account, and when I try to log back in, I get an unverified account message. However, I can log in with my new password on the Suddenlink.net web site. When I called Suddenlink customer service center, they informed me since I can log in on the Suddenlink site, it's not their problem that I can't log in on a third party application. I deleted the account in Mac Mail, and tried setting it up again, but I get the same unverified account information. I've read where others have had this issue while running El Capitan, but I'm running Catalina, and having the same issue.