Repeated incorrect/expired credentials message at login despite resetting password

I’ve tried to login in with my correct password, it tells me it’s incorrect/expired credentials, so I reset the password. Repeat issue all morning. I’ve now reset my password 3 times but still receive the same error message. It advised online to wait 90mins but still no luck. I’m trying to log-in to reply to a message about a bug that’s been going on for 3 years but can’t get logged in, their live chat bot is useless and there’s no way to contact them as far as I can tell. Has anyone had similar or know how to get around this issue? Appreciate the assistance!