Unable to log Into Discovery.Cloud and Admin Console

Hi, we have around 10 users who need to be able to access the sites Discovery.Cloud and the Admin Console. When we use our previously working credentials, we receive a password or user name incorrect error. When we reset the passwords using the online link, the reset is successful and we receive the confirmation email but still hit the same problem. 

We also see the Captcha code when trying to log in but that simply refreshes on completion and refuses to log us in. No other errors are shown. Both Edge and Chrome are affected and I have cleared the browser cache.

As this also affects our standard admin account we cannot simply manually reset passwords.